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Honda Jazz Forums => Honda Jazz Mk1 2002-2008 => Topic started by: RichardA on May 22, 2008, 09:57:04 PM

Title: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: RichardA on May 22, 2008, 09:57:04 PM
As per title...

You can use Google to convert from L/100km to MPG.

Please state if you wish the type of driving you do.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: RichardA on May 22, 2008, 10:00:00 PM
Typically getting 47mpg on the trip computer readout using regular Unleaded (usually from Sainsbury's or Esso), driving around 35-40 miles per day on mainly A/B-roads with some dual carriageway and urban traffic.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest464 on May 24, 2008, 09:46:27 AM
Hi,
Based on my last 3 tanks of petrol, full to empty light on each time my computor reads 52.9mpg.
50% of motorway driving at under 75 mph, the rest journeys of between 5 to 20 miles mixed driving. I've done 29,000 miles in 15 months from new so i have a pretty good idea of what my Jazz should do to the gallon.
The best i have ever seen is 64mpg on a run from Sheffield to Dover through the night keeping to about 65 mph.
The worst I have had is 46mpg during a very cold period doing short journeys.
My car has the 1.2 engine.
Great web site but not much to report as they don't go wrong very much!!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: wil on June 05, 2008, 03:00:16 AM
Only seem to around 38-40mpg of mixed casual driving.
Mines a 1.4 CVT though
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: RichardA on June 20, 2008, 04:43:02 PM
After two tankfulls of super unleaded (thanks to Sainsbury's money off fuel vouchers!) my mpg improved although going back to normal unleaded has had no effect. Therefore, it appears that whilst super unleaded hasn't improved mpg over normal 95RON unleaded, it perhaps 'cleans' the system out.

My trip computer is now reading at fill-up around 48/49mpg, often staying in the 50's for fair amount of miles.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest164 on June 30, 2008, 10:24:33 PM
I am 1.4 SE CVT-7 driver and I do a 100 mile round-trip daily communte between two moderately rural towns. I would classify the driving I do during the commute as town and country. I regulary obtain 52-55mpg over every tankful and I have seen this behaviour over the 73,000 miles I've run my 2005- model year Jazz.

My previous 2003 model year Jazz used to regularly get 55-58mpg over the same route over about 68,000 miles.

I attribute the better MPG figure to the 2003 year model to having had a throttle-by-wire throttle whereas the 2005- year model has a throttle cable. I think that when the engine computer unit has full control over fueling it does a better job than my foot does. And it's just a luck of the draw whether you get throttle-by-wire or throttle cable when you buy a Jazz :)

Even so, throttle cable or wire, both cars returned fantastic MPG figures which I attribute to the iDSI and CVT-7 technology, and using quality fuels, with one tankful of V-power or BP Ultimate, every month to keep things clean and regular Honda servicing by a brilliant Honda dealer. Of course driving smoothly, with good attention to road conditions and being sure to be progressive with the throttle helps too :)

It's really fun with Jazz trying to tease out ridulously good, almost diesel like MPG figures! Holidays are best - here I share peoples experiences of 65MPG and more :)

Long may Honda keep the technical innovations coming :)

Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: bill888 on August 01, 2008, 05:03:36 PM
I have a 2007 CVT auto.

Very short trips around town, it returns no more than 37mpg on the trip meter, which is about 35-36mpg at the pumps.

On motorways with a light foot and keeping speed no more than 70mph, I've never seen more than 47-49mpg on trip meter.  It works out about 46mpg at the pumps.

Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Geoffers on August 01, 2008, 06:08:55 PM
I have a brand new 1.4 manual. The trip is consistently over-reading by 2 to 4 mpg compared to what it takes to refill the tank and the actual mileage.
Trip = 46; actual = 44!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jazzfan on August 18, 2008, 08:02:44 PM
1.4 S Jazz no aircon fitted with a full set of Michelin Energy Saver Tyres. Fill to fill mpg meter showed an average trip mpg over 397 miles of 56mpg.  Best meter reading was a return trip from Westhaughton near Bolton to Nuneaton, after filling up with Shell, of 71.8 mpg over 99 miles.  Photo available to prove.  Remaining 298 miles were mostly local and return journey to work (5.5  miles each way) and average on mpg meter dropped to 56 mpg. 

Sounds great doesn't it?  But when I filled the tank, the real consumption came out as 46 mpg.  disappointing or what!  Next step is to check the odometer. 

Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: RichardA on August 19, 2008, 10:43:25 AM
Last time I filled up I'd used just over half a tank of Esso regular unleaded: 287miles, 24.7 litres, 52.3mpg according to Excel spreadsheet or 49.9mpg on trip computer.

Normally I wait until the low fuel light comes on but on this occasion I had a Sainsbury's money-off fuel voucher to use before it expired. I don't know if these figures would be quite as impressive if I had waited until I needed a full tank.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Geoffers on August 19, 2008, 11:23:40 AM
These are the mpg figures for my car since new. Each pair of figures represents a fill-up!
Actual/Car
45.0/45.0
44.1/45.0
45.0/46.4
45.4/47.4
44.0/47.7
40.8/42.9
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on September 08, 2008, 04:58:39 PM
Like most fuel economy readouts the one on the Jazz has an update period (sampling time) it probably takes a reading about every 10 seconds and updates the display, this means that if you are an erratic driver (always accelerating and heavy braking) it can miss out on peaks and the car display will be optimistic compared with your actual consumption. On the other hand if you are a smooth driver, not only will you get better mpg anyway, but the display will be more accurate.

Remember every time you use the brakes you are wasting fuel, and the harder you brake the more fuel you are wasting.

Rapid acceleration burns up the fuel like nobodies business, much more than sustained speed.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on September 08, 2008, 05:07:56 PM
I commute 50 mile round trip 5 days a week, mixed A-roads and town, and driving in a moderately careful way (changing up early, coasting where possible and staying below 60mph) can easily get 57 to 58mpg out of my 1.4SE manual Jazz.

This is not from the mpg display, but by petrol used / miles done.  The mpg display seems to read anything up to 4 mpg optimistic.

Once I zeroed the trip after a couple of miles (once the engine was warm) and got over 70mpg on the readout when I reached work - I know that this is 'cheating' but just wanted to see the result.


Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: RichardA on September 28, 2008, 04:31:09 PM
After refilling I got up to 73mpg on the readout! I know it won't sustain that figure (it dropped to 71 as you can see once I stopped) but it's fun to see on the display!

[edit by admin 18 Dec 2010 - removed missing image]
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: trebor1652 on October 22, 2015, 09:23:02 PM
Mk1 2006 CVT 38 to low 50's
Only filled up once with the mk3 CVT just short of 40 mainly short journeys.

Sent from my XT1039 using Tapatalk

Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest5934 on February 26, 2016, 11:30:19 AM
Computer reading 45.6 but calculated at 41.9mpg using Shell.
Just filled with Shell V power so see how that does?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest4312 on April 21, 2016, 07:58:08 PM
just changed plugs /air filter/shell v power and now works even better and mpg for same journey 7 mile each way mix of 30 mph(majority) to short run of 60 -now 46-49 :) mpg not too bad for cvt .Prior to this on normal shell average 39-42
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: JRHPNG on April 22, 2016, 11:26:53 AM
5.8-6.9 ltrs per 100km.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest5589 on April 22, 2016, 12:17:39 PM
Computer reads 54mpg but manual calculations come to about 51mpg over past 800 miles
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: JazzyJJ on May 16, 2016, 03:00:34 PM
I've had my 2007 Honda Jazz for about 1.5 months. It's a manual. I like it.

My journeys are mainly 6 miles to work and back - so a round 12 miles a day in moderate north London traffic. I've filled it with super unleaded since I've had it - but today I put in regular unleaded.

The computer says I'm getting 37-40mpg but my iPhone app says I'm getting 32mpg. I'm alittle disappointed but overall I like the car.

The first time the fuel light came on I could only put in 32ltr. The next fill up's after the fuel light was on I got 38-40ltrs. Today the fuel light came on and I got 45.5 liters in - weird that there can be a 17ltr difference after the fuel light comes on. Maybe the first time was a glitch.

I have some questions but I'll post them later in separate threads.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: VicW on May 16, 2016, 04:06:32 PM
Today the fuel light came on and I got 45.5 liters in - weird that there can be a 17ltr difference after the fuel light comes on. Maybe the first time was a glitch.

I thought that the Jazz tank capacity was 42 ltrs ?

Vic.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: JazzyJJ on May 16, 2016, 05:00:42 PM
Today the fuel light came on and I got 45.5 liters in - weird that there can be a 17ltr difference after the fuel light comes on. Maybe the first time was a glitch.

I thought that the Jazz tank capacity was 42 ltrs ?

Vic.

Yep, me too. Now that you mentioned it maybe the Shell petrol station I went too fiddle the pump to say I used more than did? I would not be surprised. I won't go there again. But my receipt says 45.5 liters at 1.099p unleaded = £50 exactly.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest5589 on May 16, 2016, 06:09:29 PM
I've had my 2007 Honda Jazz for about 1.5 months. It's a manual. I like it.

My journeys are mainly 6 miles to work and back - so a round 12 miles a day in moderate north London traffic. I've filled it with super unleaded since I've had it - but today I put in regular unleaded.

The computer says I'm getting 37-40mpg but my iPhone app says I'm getting 32mpg. I'm alittle disappointed but overall I like the car.

The first time the fuel light came on I could only put in 32ltr. The next fill up's after the fuel light was on I got 38-40ltrs. Today the fuel light came on and I got 45.5 liters in - weird that there can be a 17ltr difference after the fuel light comes on. Maybe the first time was a glitch.

I have some questions but I'll post them later in separate threads.

That is quite weird. Have you checked tyre pressures and air filter? Yesterday in very early morning traffic on A406 I was getting an 'indicated' 65mpg followed up by 55mpg on a motorway run .. .calculated manually I got about 51mpg on average with 70% motorway driving.

Also I have never been able to put more than £36 worth of fuel in (@99p/l) yesterday needle was right where the light should have come on any second and the first click of the nozzle was at £33 (@1.09p/l)

You might want to try a different fueling station
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest5846 on May 16, 2016, 07:05:05 PM
I've a mt 1.4 I-Dsi and I get 30mpg pretty consistently although I drive everywhere like I stole it and most of my driving is round the doors, did do a long motorway journey though and managed 45mpg averaging 85-90
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Sharon on May 28, 2016, 11:09:38 PM
After refilling I got up to 73mpg on the readout!

 ??? WOW, Really?  I get 38-40 at best.  >:( 

Are you driving downhill, with the engine off?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest1372 on May 29, 2016, 02:18:55 AM
Average use 47mpg right now (Summer / Winter makes a huge difference for me)
Best ever eco drive: 3 mile Tesco > home on deserted roads at night 68mpg with a feather foot and green lights plus a bit downhill at the end bumped it up to 72mpg.
--
TG

[attachment deleted by admin]
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest6092 on June 13, 2016, 03:14:20 PM
08 number plate, Mostly use in the city, barely over 30mph, computer reads 46.5-47MPG
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest5970 on July 21, 2016, 12:32:53 PM
2002 1.4 SE manual: 54-55mpg overall on my regular commuting runs of around 25 miles each way on A roads/country lanes. Just manages 60mpg average on long motorway/A road runs. Figures from receipts & mileage reading. Fuel consumption meter surprisingly on the mark. Aircon seems to cost around 2.5mpg.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: gtd2000 on August 05, 2016, 09:28:40 PM
2002 DSI 1.4L SE with amost 130,000 miles on the odometer, owned for around 4 years.

Generally returns around 55MPG, running around this rural area.

With regards AC and whether or not it affected the fuel consumption, the car was always averaging around the mid 50's mark but on a run with 4 adults and one young child, plus AC on full bore the car returned 62.1MPG :)

Since then, the record has been 73.1MPG but I once reset the meter at the top of a hill and saw 150MPG but that doesn't count at all :)

I can regularly achieve high 50's to 60MPG on A roads but it dips down to 46~50MPG on the motorway.

This car gets way better economy than my old KIA Picanto but it had some very quirky MPG results that were all over the place.

I drive a Hyundai i20 CRDi most of the time and that's had as much as 82.6MPG but usually returns mid 60's to 70MPG.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest6230 on August 21, 2016, 07:37:10 PM
In my first 600 miles it's done 52.2mpg on V Power with full mix of driving, well pleased.  ;D
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Century21 on December 12, 2016, 01:17:02 PM
I had a 2004 plate 1.4 SE and in urban driving managed around 20mpg... lots of starting and stopping.  My current 2008 1.2 Mk1 does around 30 for the same trips.  It was bought with 6000 miles on the meter and it's immaculate, so I think it's either my driving style or the Jazzes don't like traffic.  :D
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on December 12, 2016, 01:56:03 PM
I had a 2004 plate 1.4 SE and in urban driving managed around 20mpg... lots of starting and stopping.  My current 2008 1.2 Mk1 does around 30 for the same trips.  It was bought with 6000 miles on the meter and it's immaculate, so I think it's either my driving style or the Jazzes don't like traffic.  :D

The Jazz should be no different in traffic to any other car with an engine,  but short journeys in traffic will kill MPG -- slow stop-start traffic and acceleration are the worst for mpg, followed by high speed.  To continually having to accelerating the mass of the car from standstill to 30 mph or there about is very inefficient. IMHO giving the car a regular run (on main road or motorway with a bit of sustained engine revs and a dose of redex injection cleaner to get the gunge and cobwebs out of it,  and some branded fuel with decent additive package) would do it good.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: John Ratsey on December 12, 2016, 02:37:10 PM
The Jazz should be no different in traffic to any other car with an engine,  but short journeys in traffic will kill MPG -- slow stop-start traffic and acceleration are the worst for mpg, followed by high speed.  To continually having to accelerating the mass of the car from standstill to 30 mph or there about is very inefficient.
I would add that it probably takes up to 5 miles (a bit less in summer) to get the engine properly warmed up and running most efficiently. Stop-start is the type of driving condition which the hybrid Mk 2 Jazz, with its relatively small battery, was designed for. Decelleration / braking pushed some energy into the battery which could then be used to supplement the engine power when accelerating. Bigger motors / generators / batteries increase the proportion of energy recovery but Honda hasn't brought the Mk 3 Jazz hybrid in the UK (it is sold elsewhere as the Mk 3 Fit hybrid). Maybe if government adjusted the taxation to favour hybrid petrol over diesel with the equivalent CO2 then Honda might change the UK product range.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on December 29, 2016, 07:20:03 PM
My 56 plate 1.2 has done 92K miles. I have owned it since July and have averaged 52 mpg for the 5k I have done. The best tankful was 57 mpg, the worst, 47 mpg. These are actual measured mpg - not what the gauge says (though it is reasonably accurate on my car). I do frequent daily short journeys of around 3 - 5 miles in town (about 4 times a day), with a couple of 40 mile open road journeys most weekends. I am finding that the mpg is a lot lower now the cold weather has come along. What I do do is leave the heater temp set at cold, until the blue warning light goes out, then set it for warm. That way I allow the engine to warm up before I warm up the heater battery. I find that this way, the blue light goes out a lot quicker.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest6599 on February 03, 2017, 05:44:35 PM
Mine's doing 45-50 mpg even though I do a lot of very short trips to the local shop!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest6436 on February 03, 2017, 11:50:14 PM
about 35-37mpg , I only do a lot of very short trips with it (about 1 mile in total stop&go city traffic) and spend some time running it before I set off in colder morning.
It's a car that's used to do school runs, dog runs, tip runs, going to local lidl and that's it. For longer trips there's bigger car.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest6657 on February 26, 2017, 04:59:37 PM
Just under 40mpg (using tank fill to fill calculation) on my 2008 MK1 Sport with CVT box.

The trip computer is slightly more optimistic than the actual, generally stating 42-43
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Sterling01 on March 13, 2017, 07:52:57 AM
This is always of interest to me. I always brim the car with fuel and run it till the low fuel light comes on and them brim it again. In my opinion, if you always drive in a similar manner, a sudden change in fuel consumption can be an early indication of something not quite right with the car. For my test I did 60% motorway, 30% A-roads and 10% B-roads, sticking to the speed limits. My car is a 2008 with 90k on the clock.
(http://www.kgcs.net/jazz/mpg.jpg)
I'm pretty happy with that result. I brimmed the car and did a calculation and it came out at 50.4mpg, so the computer in the car is pretty damn close.

I'm going to do a full service on the car soon, only using Honda parts. All filters, spark plugs, oil, etc. It will be interesting to see if it makes a difference.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: u587162 on March 20, 2017, 01:33:56 PM
I get about 250 miles on a full tank on the second hand car that purchased with about 90k miles on it (automatic).

I believe the fuel tank is only 45 litres capacity too right?

Does that sound like poor mileage or good for a whole tank?  Wife only drives it locally to drop the kid to school and for shopping.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: VicW on March 20, 2017, 03:35:07 PM
The tank capacity is 42 litres, just over 9 gallons. Your consumption depends on usage.Do you mean by a full tank that is what you get between fill-up and low level light coming on? The Jazz low light is very pessimistic generally coming on with about 7 litres left, best part of two gallons.
If so your consumption is about 33mpg but if you are only doing short journeys in traffic with lots of cold starts that is not unusual.

Vic.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest1372 on March 20, 2017, 06:47:56 PM
250 on a full tank sounds low, but probably OK for town miles or 85 mph down the M1.  Driving at 60 ~ 65 will see much better results.  My rule of thumb is 10 miles per litre (350 miles / 35 litres per fill) if away from favourite points paying petrol station.
--
TG
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: u587162 on March 20, 2017, 06:48:37 PM
yeah i think its when the light came on.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Eddie Honda on March 21, 2017, 02:12:39 AM
250 to light is fine for all local short runs.

Tank is a nominal 42 litres. Least ours has been filled with is 30.61 litres, most 47.96. Generally gets filled 36 to 40 litres.

Worst consumption was 8.74 l/100km (32.3mpg) and that was hammering it on a motorway with a roofbox on.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on March 21, 2017, 07:39:35 AM
I get about 350 miles before the light comes on. The most I have ever put in to top up (first click off of the pump) is 7.9 gallons/36 litres. I do mainly town driving, and over the 6K miles I have done since buying the Jazz I have averaged 52 mpg.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest6709 on March 24, 2017, 08:04:15 PM
So far, after only 4 days of driving my 2005 1.5 CVT-7 import, the best I've managed on a on-way trip to/from work (33 miles) is 57.6 mpg (or 20.4 km/l as per the ODO).

Sampled over a mixture of village, B roads, Motorway and A roads driven very sedately.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest6811 on May 01, 2017, 02:24:08 PM
Hi all I've got a 06 plate 1.4 auto mainly used for school run getting 42.6 but on longer runs getting 49.2 if we get stuck going into town (a lot of start stop up to 20 mph then 38.??)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest4219 on June 08, 2017, 11:32:00 PM
02 Plate CVT. 43000 miles.
Over the last 850 miles the on board indicator is showing 47.1 mpg.  That's with more long runs than usual. Ordinarily it's used for local shopping, when we get circa 40  mpg.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on June 14, 2017, 04:20:36 PM
Topped up today, after a fortnight of my usual driving, which included my MOT and a 3 mile queue on the motorway, and was amazed and delighted to achieve 60.3 mpg. It shows what the warmer weather does. It has also been thundery and humid here, which is supposed to lead to greater engine efficiency.
Never had such good mpg figures since I parted with my FIAT 126, many years ago.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on June 16, 2017, 08:27:53 AM
Yesterday I had a trip to Danderhall and then into the centre of Edinburgh. My return was just as the traffic began to build for rush hour, and my 45 mile trip took 2 hrs 40 min. However, I am delighted to report that my mileage indicator is still showing 58.9 mpg. But what a nightmare of a journey. I know many of you will experience that on a daily basis. I really miss my Automatic in traffic like that.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest6981 on June 22, 2017, 09:54:52 PM
I'm getting around 52mpg from my 2007 1.4 DSI SE manual which I'm pretty pleased about  :D

That's a mix of town and motorway driving.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on July 19, 2017, 12:24:58 PM
Since fitting my ScanGauge E I have been gleaning quite a bit of information regarding my motoring.
Today was my usual motoring day. I drove my wife to her work, first thing, returning home after, then picked her up at the end of her shift. The miles are all in town, a couple of sets of traffic lights each trip, reasonably busy traffic. Other than cold or poor weather it cannot get much worse.
Here are my figures for today's motoring.

Distance travelled: 8.0 miles
Petrol used: 0.16 gallons
Cost of petrol: £0.80
Average mpg: 49.7 mpg
Average speed: 17 mph
Max speed: 32 mph
Maximum revs: 2576 rpm
Max coolant temp: 77°C

Not too shoddy in my opinion.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: VicW on July 19, 2017, 03:58:23 PM
Jocko,  How does the Scan Gauge E work out the cost of the fuel, do you have to put in the petrol cost or does it use a ball park figure, if so what ?

Vic.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on July 19, 2017, 06:03:38 PM
Each time you top up the tank it tells you how much it thinks you have put in. If necessary you correct that figure (after initial calibration it should be pretty close). It then displays the price per gallon from the previous time. You either save it of correct and save it. So that way it knows you have 9 gallons of petrol (in the case of a GD5), and it cost £5.11 a gallon or whatever.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on July 21, 2017, 09:51:20 AM
Just done a top up this morning, the first since fitting my ScanGauge so I was able to set the calibration.
366 miles, 26.79 litres, 62.1 mpg. Not bad, since I have been back to the daily town journeys this past week.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on July 22, 2017, 09:42:07 PM
More ScanGauge info for today's run.

Distance travelled: 93.9 miles.
Average mpg: 57.2 mpg
Average speed: 34 mph
Max speed: 57 mph
Maximum revs: 3431 rpm
Max coolant temp: 85°C

This was mainly dual carriageway with come B road and a bit of town driving. Temp was about 18°C
but it was windy and heavy rain with standing water. On the return journey the traffic was really slow, mainly I guess due to the heavy rain. That always slows the traffic down (no bad thing). I was really quite pleased with these figures, though I find it rather difficult to get the mpg up on dual carriageway/ motorway driving.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: sparky Paul on August 06, 2017, 11:07:43 PM
After a few more little jobs done on the Jazz, including the squeaky clutch and tightening a few things up under the bonnet, we all went visiting family today and I thought I would reset the trip and see what how the mpg played out.

Four of us and the dog in the car, 50 mile round trip, steady run on mainly rural roads. Display showing 53.7 mpg on return, not too bad I thought!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 07, 2017, 07:21:59 AM
Filled up the tank today after almost 3 weeks driving.
Car's fuel consumption gauge said 59.6 mpg
ScanGauge said                           57.1 mpg
Calculated (and accurate reading) 59.1 mpg

Considering we are now back to the daily grind, with most of my miles in town, 4 miles at a time and a cold start each time, I am really pleased with that.
This time I filled up with 97 RON Super Unleaded (Sainsbury's), to see if it makes a difference. It may be all in my head, but on the three miles back from the filling station the car seemed to have a bit more oomph. As I said. probably all in my head.
I added a half bottle of Redex Petrol Treatment to the full tank. That's the third tankful I have done that, but so far it doesn't appear to make any difference. After I use the other half of the bottle I think I will give it a miss.
What I did notice is that the ScanGauge, using the OBMII data, had calculated that I had driven 9 miles less than the odometer said I had. There does not appear to be any means of calibrating that.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: sparky Paul on August 07, 2017, 09:09:50 AM
This time I filled up with 97 RON Super Unleaded (Sainsbury's), to see if it makes a difference. It may be all in my head, but on the three miles back from the filling station the car seemed to have a bit more oomph. As I said. probably all in my head.

I don't think you are imagining it. The extra octane should give you a bit more power, and you correspondingly require a fraction less throttle opening for any given driving situation, which should increase your mpg slightly. Anecdotal evidence suggests in some engines, it can balance out the extra cost at the pump, as well as the obvious benefits of the car being smoother to drive. A mate of mine swears by it, he reckons he gets 5-10% more mpg.

I think Redex had a use when engines had carburettors and weren't so clean burning. Nowadays, engines run so cleanly - when did anyone last de-coke an engine? I've took heads off modern engines that have done 100K+ miles, and they're as clean as a whistle. Fuel tanks don't seem to collect the same deposits in the bottom either, that must be down to improved fuel quality.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 07, 2017, 09:16:04 AM
I had a £2.50 off voucher for my petrol (I got one a month, for the year, after insuring with Sainsbury's Bank), so it actually worked out cheaper than 95 RON from either Morrisons or Asda. I don't think Morrisons do 97 RON, here in Kirkcaldy. Not sure about Asda.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on August 07, 2017, 12:25:11 PM
I don't think you are imagining it. The extra octane should give you a bit more power, and you correspondingly require a fraction less throttle opening for any given driving situation, which should increase your mpg slightly. Anecdotal evidence suggests in some engines, it can balance out the extra cost at the pump, as well as the obvious benefits of the car being smoother to drive. A mate of mine swears by it, he reckons he gets 5-10% more mpg.

I think Redex had a use when engines had carburettors and weren't so clean burning. Nowadays, engines run so cleanly - when did anyone last de-coke an engine? I've took heads off modern engines that have done 100K+ miles, and they're as clean as a whistle. Fuel tanks don't seem to collect the same deposits in the bottom either, that must be down to improved fuel quality.

I regularly used to swop between 95 and 97 when I was doing long daily commutes and did notice both the smoothness / liveliness and mpg improved on higher octane, and presumably higher octane was keeping system clean as well,  it was a good test because daily commute replicated distance and traffic conditions and because it was all year round it also covered different ambient temperatures  and humidity etc.

People still see redex as a substance to remove carbon from engines,  but that would be when you tipped it into carb and filled the whole road with smoke for an hour.  It is now called 'fuel system' or 'injector cleaner' and its job is to dissolve the gum / lacquer that dinosaur juice can leave behind when it evaporates,  low annual mileage cars used on short runs are most prone to injectors getting clogged (like limescale clogs holes in your shower head) - It is always worth a try if having problems as it is fairly cheap and easy to use.  I use it in my mower and motorbike as a 'fuel conditioner',  especially over winter and find that they start easily after a layup (they never used to),  also sometimes put some in our cars,  when my wife did mainly short local journeys it seemed to improve mpg and general running.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: VicW on August 07, 2017, 03:57:00 PM
A point to remember when trying higher octane fuel. If you put half a tank of 97 on top of half a tank of 95 you have got a tank of 96
It will take you two or three fill ups with high octane before it's neat 97/99, whatever you are using.

Vic.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 07, 2017, 04:05:22 PM
I realise that, though I always run my tank right down before I refill.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on August 07, 2017, 05:44:53 PM
A point to remember when trying higher octane fuel. If you put half a tank of 97 on top of half a tank of 95 you have got a tank of 96
It will take you two or three fill ups with high octane before it's neat 97/99, whatever you are using.

Vic.

My tank was continually getting empty as I was doing about 450 miles a week just commuting.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on August 07, 2017, 09:54:14 PM
I've often wondered if there is any difference between the supermarket "super" petrols (Tesco Momentum for example) and the branded ones. Octane, obviously not, but in terms of additives.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 07, 2017, 10:01:39 PM
I've bought supermarket fuel, exclusively, for the best part of 40 years and never had the least bit of bother. That's not to say it is as good as the likes of Shell or Esso, but it has never given me any problems. Next time I intend trying Shell (it is Shell we use in the works vans), so I'll see how it goes.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: sparky Paul on August 08, 2017, 03:39:11 PM
I think there's less difference in the petrols now than there was when supermarkets started selling. I had a Vauxhall back then with the red top 2 litre, and it did not like Tesco unleaded at all, so I ended up with mountains of tiger tokens from the Esso garage. These days, however, I think that while Shell, Esso, etc. may still be better quality fuel, the differences are marginal.

Diesel is another matter, our Terrano still does not like our local Morrisons' diesel, especially in the winter when it gels terribly. Some also suspect that lack of lubrication in cheap diesels has some part to play in common rail injector pump failures in cars that are particularly prone to this, Renault 1.5dci, Ford 2.0 TDCi for example. Some cars fail catastrophically at lowish mileages, whilst others go on to do hundreds of thousands without a problem, and some say the fuel has something to do with it.

It's also worth noting though that Tesco Momentum is 99 RON, one of the highest available on pumps here.

Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: MikeG1944 on August 09, 2017, 08:57:25 AM
It's the age old argument and everyone has their opinion on cheap fuel, but the way I see it is if the cheap supermarket stuff is only 2 or 3p a litre cheaper, and the top brands give you 2 or 3% more mileage, due to extra additives and lubricants, then there's no saving buying the cheap stuff. The top brands are also supposed to make your engine last longer so that's a plus.

A local taxi firm here stopped their drivers using the cheap stuff as it was causing valve problems with their cars. Previously had no problems when using the top brands.

As we have a BP station just 100 yds from our house we tend to use that.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 09, 2017, 10:01:26 AM
Yesterday I had to make a trip over to Danderhall, on the south side of Edinburgh. I then had a jaunt into the city, before returning to Danderhall then returning home to Kirkcaldy. It was a mix predominantly country roads, dual carriageway, with a little motorway and the city driving.
There was quite a bit of congestion coming out of the city, and initially on my journey home, however the traffic leading to the Forth Road Bridge was unusually light which made a change (new bridge opens this month).
Add to this my normal early morning commute to take my wife to her work, plus picking her up late am, and I averaged almost 62 mpg, according to my ScanGauge. Too early to say if there had been any improvement since going to 97 RON, but I'll keep you informed.
These are the figures for my day's driving:
Average mpg: 61.8 mpg
Max coolant temp: 85°C
Distance travelled: 93.2 miles
Maximum revs: 3377 rpm
Max speed: 64 mph
Average speed: 30 mph

(http://i.imgur.com/p1NTnct.jpg)

(http://i.imgur.com/0FNXMET.jpg)


Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 10, 2017, 07:08:37 AM
This morning I set a PB for the morning commute. Starting from a cold start, with car having been sitting for 18 hours (it is garaged, but it is starting to get chilly here overnight), my 3.9 mile town driving trip returned 60.0 mpg (4.71 l/100 km). And it never even got up to temperature!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest7024 on August 11, 2017, 05:36:28 PM
2002 se  average mpg 54
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 11, 2017, 05:58:42 PM
2002 se  average mpg 54
That's a good figure.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: sparky Paul on August 13, 2017, 09:17:58 PM
According to the mpg-ometer, our is hovering mostly between 52.3 - 52.6mpg, occasionally creeping up over 53mpg. For mixed driving, I'm pleased with that.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 13, 2017, 09:33:12 PM
I find my mpg-ometer pretty close to my calculated figure. It is slightly optimistic but only by about 1%.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on August 13, 2017, 10:17:03 PM
Great photos!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: sparky Paul on August 13, 2017, 10:25:29 PM
Haven't run enough petrol through to check the accuracy of the mpg-ometer yet, but it's looking about right.

I agree about the pics too, cracking photos! I can't wait to see it for real, probably during October half term week.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: gtd2000 on August 14, 2017, 09:11:50 AM
Did some checking of the "new" Jazz (2006) yesterday on a run from St Boswells to Berwick upon Tweed (Spittal).

Reset the trip at St B and found that at 40mph on the flat you could achieve 70+MPG. (My old record was 73.1MPG with the original 2002 model).

By the time we arrived in Spittal I was showing 65.8MPG.

Arriving home in the evening MPG was back down to 56MPG.

The new Jazz seems to be able to get good MPG but not nearly as easily as the old one. The old one would manage 60+MPG on a Sunday run without any difficulty.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on August 14, 2017, 09:29:11 AM
Great photos!

Yes,  striking photos.

We saw them starting the new Queensferry bridge when we were in Scotland a few years ago , cable stay rather than suspension design.

I think suspension bridges are going out of fashion due to the fact that the large single cables required to support the road deck are prone to corrosion and once the bridge is up and running it is impossible / extremely expensive to replace the cables and would require the bridge to be closed for a long time.   All main UK suspension bridges  (The Forth bridge, Severn bridge, Humber bridge etc.) have microphones fitted to the cables and the number of inner steel cores that snap are monitiored,  the best that can be done is to blow dry air up the cables to slow the corrosion.   

Cable stay bridges like the new Forth (Queensferry) bridge can have individual cables replaced while in service, so are liable to last a lot longer.  They are more like the old 'cantilever' design original Forth rail bridge.  Would be interested to know how long the Forth suspension bridge will last before major repairs needed.

Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 14, 2017, 10:19:53 AM
The reason they built the new one is to replace the old one, because of cable corrosion. Next month the old bridge will be closed to all but buses, cyclists and pedestrians.
Having said that, since commencing building the new bridge they have discovered that the corrosion is nowhere near as severe as they thought.
I imagine that the long term plan is to do repairs to the old bridge, then have them both back in commission, as one bridge is not enough. The new bridge will simply take the jams that were on the old bridge. It will still be four lanes of northbound motorway traffic squeezed down into two.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 24, 2017, 07:59:17 AM
Filled my tank today, and after 445 miles of my normal mixed motoring the calculated fuel consumption figure worked out at 60.7 mpg. I topped up with Shell V-Power today, but think I will revert back to supermarket Regular. Today's top up cost £5.95 a gallon, whereas the supermarket regular is currently £5.21 a gallon.
I added the last half bottle of Redex Petrol Treatment to the full tank, but don't think I'll bother using that in future, either.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on September 01, 2017, 07:15:11 PM
Topped the tank up this morning. My calculated mpg was 60.9 mpg. According to Fuelly, my average for the last 3 months is 58.9 mpg. We'll see what happens once the cold wet winter gets here - next Tuesday!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest4871 on September 01, 2017, 07:35:33 PM
I think you can be very proud of a solid 60 mpg on a 10 year old car.

Quite an achievement!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on September 16, 2017, 04:31:53 PM
My fuel efficiency has dropped off considerably, after replacing my front tyres. I wondered if I had a poor seal and a tyre was deflating, but that wasn't the case. I have also checked for a dragging brake, but everything is okay in that department. It is all pointing to the tyres, as my ScanGauge started to display the poorer figure on my return from having them changed, and has not improved since.
The thing is, I am not hard on tyres, and, barring accidents, they will probably see the car out! I will just have to live with them, as I am not in a position to change them just because of poor mpg. I'll just have to suck it up.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on September 16, 2017, 06:31:22 PM
My fuel efficiency has dropped off considerably, after replacing my front tyres. I wondered if I had a poor seal and a tyre was deflating, but that wasn't the case. I have also checked for a dragging brake, but everything is okay in that department. It is all pointing to the tyres, as my ScanGauge started to display the poorer figure on my return from having them changed, and has not improved since.
The thing is, I am not hard on tyres, and, barring accidents, they will probably see the car out! I will just have to live with them, as I am not in a position to change them just because of poor mpg. I'll just have to suck it up.

What tyres did you have on before and what did you replace them with ?  How much has MPG dropped ?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on September 16, 2017, 08:47:28 PM
Original tyres were Firestone Multihawk 2. New tyres are Riken, fitted by the Honda dealer. For what I can find on line, the Riken tyres are about the worst for economy they could have fitted. Don't know for sure until I do a top up and calculation, but it looks like a 5 - 10% drop in mpg.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: sparky Paul on September 16, 2017, 09:52:18 PM
Did you choose the Rikens Jocko, or do do they just bung on what they can get?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on September 16, 2017, 10:11:07 PM
They were going to fit Hankooks but couldn't get them so fitted the Rikens, I just got what they fitted. I have no complaints other than the fuel consumption. I'll do my sums and maybe get something else. I can always stick them in the back of the garage for emergencies. Even have a look in the breakers for a pair of steel wheels (that's what I have already).
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: sparky Paul on September 17, 2017, 12:04:31 AM
Well, there's some sense in that if it's making that much difference. Rough back of a fag packet type guesstimation, 10% loss of mpg is worth about £100 per 10,000 miles?

You have to weigh it up against the cost of something like the Hankook Ecos, which are quite a bit dearer than the Rikens. There seems to be quite a lot of these Riken tyres about at the moment, cheaper than normal. I saw them around £60 a pair to fit mine - 185/55x15 supply only.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on September 17, 2017, 09:19:09 AM
I replaced Michelin ES+ on my Civic with Avon ZV7 tyres and they are much grippier,  just as quiet but a little (only a little) stiffer in the sidewall - when you consider they cost £50 instead of £76 that makes a difference on 4 tyres over £100.

Have not noticed any change in MPG, but have noticed how much better they are in wet and dry grip (with ES+ used to easily spin the front wheels on some of the junctions by where I live,  but takes a deliberate over-use of power now to do it) also very good directional stability.  Not so worried about getting mega miles out of tyres anymore (which is why I always got ES+) as I have retired and gone from 25 to 30K a year down to less than 10K.

Avon don't seem to do the 185/65R16 fitted to some Jazz (including my wifes GE) but I would consider them if they did. 
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on September 20, 2017, 09:33:57 AM
Just filled my tank up, the first complete top up since fitting the new tyres and I only got 55.7 mpg. I cay "only", but it has been around 60 mpg for the last few top ups. Still better than my running average over my ownership of the vehicle though.
This time the dashboard computer was wildly out at 60 mpg.
So the new tyres have reduced my fuel efficiency by about 3 - 5%. Disappointing, but not as bad as I first thought.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: MartinJG on October 03, 2017, 08:33:51 PM
What pressure? I think the recommended is @ 32 but I have mine at 34-35. I always up the pressure by a few pounds. Much better for my taste in every way except maybe an incy whincy bit of comfort. Better wear and handling and almost certainly improves MPG. Not so good on icey conditions of course but easily adjusted.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on October 03, 2017, 08:44:33 PM
What pressure? I think the recommended is @ 32 but I have mine at 34-35. I always up the pressure by a few pounds. Much better for my taste in every way except maybe an incy whincy bit of comfort. Better wear and handling and almost certainly improves MPG. Not so good on icey conditions of course but easily adjusted.

You may find that your tyre tread will wear more quickly in the centre of tyre if pressure is higher than recommended. Wide race car tyres are deliberately moulded to be concave so that pressure makes the tread flat,  normal car tyres start off flat and too much pressure makes them convex, which causes extra wear on centre as well as affecting braking due to reduction in contact patch size.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on October 03, 2017, 11:10:24 PM
What pressure? I think the recommended is @ 32 but I have mine at 34-35. I always up the pressure by a few pounds. Much better for my taste in every way except maybe an incy whincy bit of comfort. Better wear and handling and almost certainly improves MPG. Not so good on icey conditions of course but easily adjusted.
I run 35 front and rear. I have read all the arguments for and against upping the pressures and decided to settle for that.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: MartinJG on October 03, 2017, 11:18:19 PM
What pressure? I think the recommended is @ 32 but I have mine at 34-35. I always up the pressure by a few pounds. Much better for my taste in every way except maybe an incy whincy bit of comfort. Better wear and handling and almost certainly improves MPG. Not so good on icey conditions of course but easily adjusted.

You may find that your tyre tread will wear more quickly in the centre of tyre if pressure is higher than recommended. Wide race car tyres are deliberately moulded to be concave so that pressure makes the tread flat,  normal car tyres start off flat and too much pressure makes them convex, which causes extra wear on centre as well as affecting braking due to reduction in contact patch size.



Yes, I am aware of the risk of over inflation. I have run the 16'' tyres (Toyo Proxes) on my Octavia at 35 for several sets of tyres with no adverse wear or performance. In fact, I got much better tyre life, handling and more even wear after increasing the pressure from the recommended 32. However, as you point out, they are actually more of a profile race style tyre. The Jazz 15'' is 'on trial' at the moment but it certainly feels much better at 34 than 32 but I will keep an eye/feel on the tread over time.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on October 06, 2017, 07:28:26 AM
Just filled my tank up, after 434 miles, and was very pleasantly surprised to record a calculated 62.5 mpg. The dashboard display was saying 61.3 mpg, so not too big a discrepancy.
I try to always use the same pump, on the same level forecourt, and stop at the first cut off (unless I am experimenting with a different fuel!).
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on October 15, 2017, 02:15:59 PM
Today I had a trip over to the south side of Edinburgh. Being a Sunday morning, the roads were reasonably quiet. I managed to get in behind a couple of HGVs at parts of my return journey (careful to keep a safe distance back), which helped push the air aside.
Here is the information for today's trip, as computed by my ScanGauge E:
Average mpg: 65.1 mpg
Max coolant temp: 84°C
Distance travelled: 86.7 miles
Maximum revs: 2957 rpm
Max speed: 56 mph
Average speed: 35 mph

Pretty pleased about that.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: MartinJG on October 16, 2017, 09:14:31 PM

Jocko

So was the drop in MPG an anomaly, if so, what do you think caused it if not the tyres? Could it have been a blip in the meter reading?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on October 17, 2017, 07:50:59 AM
The only true measure of my mpg is when I fill up at the pump (same one every time if possible, and on the same level forecourt) and calculate my mileage for that complete tankful. What the ScanGauge shows me is all relative. The instantaneous read out tells me how I am doing, but is not a definitive figure. The same goes for my daily or trip mpg. It shows me whether I am better or worse than yesterday. It is not a million miles out, but the calculated figure is better (and the average over several tankfuls better still.
The accuracy of the ScanGauge improves with every tankful (calibration adjusted each time you fill up to steadily improve the error), but unfortunately I botched the setup at the beginning of September, and had to do a remedial setup on half a tank, to get reasonable numbers again. Because I only have to fill my tank twice a month it takes a spell before the numbers are accurate again.
The reason I botched things is I was trying to rush on a busy forecourt and stuck too many gallons into the equation! I now fill up, collect my receipt with the numbers I need, then pull into the nearest bay (supermarket car park) to do my sums and enter my data.
So all in all I think the accuracy of the data was the biggest factor, though I have now added a couple more psi to the tyres (they don't get so hot in the winter) and I have developed a modified driving style for dual carriageways, based on controlling my Manifold Absolute Pressure. Every little thing helps.
Regarding the average over several tanks. Fuelly.com, where I record my top ups, gives the average over the last 10 tankfuls, and my figure is currently 60.0 mpg (my Spritmonitor numbers, shown beside my avatar, are for my time of owning the vehicle).
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: MartinJG on October 17, 2017, 11:36:38 PM

Jocko

This is total commitment. Dedication to perfection and nothing less!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on October 21, 2017, 02:11:37 PM
Managed my best ever mpg today. 67.8 mpg over 76.6 miles. Numbers are courtesy of ScanGauge E. Interested to see what my calculated mpg works out at, when I fill up later next week.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: DesmoDan on October 22, 2017, 07:00:56 PM
We've only had our jazz a couple of months so I'm still learning how to get the best out of the cvt box .
So far I'm getting  40 around town , which is more stop than start at the moment and 48 on a run to north Wales to visit family.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on October 25, 2017, 07:50:01 AM
Filled up the tank this morning. Miles from last top up to fuel warning light coming on were 432. Calculated mpg was 57.6 as against a dashboard display figure of 60.1. Slightly down this tankful, but that was down to more short trips in town than the previous tankful.
I do an sPC check on my fuel consumption using Western Electric rules, and that falls above the average and nowhere near cause for concern.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest7218 on November 07, 2017, 06:24:52 PM
I've only just got my first Jazz. So far keeping it between 44-46 mpg, but looking forward to seeing if I can push that figure north... it's a 56 plate with 71k on the clock, so I'm not expecting miracles :)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: sparky Paul on November 07, 2017, 06:46:17 PM
50+ mpg shouldn't be too hard to achieve, our 1.4 averages around 52-53mpg knocking about and it's done twice the mileage yours has.

Best I've seen over a lengthy journey is just over 60mpg, but that was a steady drive and a feather foot most of the time.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: RScorpio on December 03, 2017, 02:03:07 PM
50+ mpg shouldn't be too hard to achieve, our 1.4 averages around 52-53mpg knocking about and it's done twice the mileage yours has.

Best I've seen over a lengthy journey is just over 60mpg, but that was a steady drive and a feather foot most of the time.
I have struggled to exceed 44-45 mpg at any point of time in the last 18 months of ownership so far and my daily drive includes some motorway driving at 60-65 mph. Is there anything special recommended that helps you get to 50+?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on December 03, 2017, 03:26:30 PM
Try cruising at 55 mph. In traffic, try and think as far ahead as possible, and avoid the need to brake where possible. If you lift off well in advance, as well as not wasting energy by braking, the Jazz goes into Deceleration Fuel Cut Off mode, where the injectors cut off the fuel completely, so you use no petrol at that time.
Fitting a ScanGauge, or the like, is the ultimate aid to great fuel consumption. I have had my Jazz for 18 months, and you can see my average mpg over that time. And most of my motoring is 2 x 7 miles, 5 days a week, all in town and traffic.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: MartinJG on December 03, 2017, 05:19:00 PM

I managed to get up to 49.3 on the gauge doing short mixed journeys during summer/autumn.  Now that we have moved into winter it has plummeted to 48.9 although it crept back up to 49 this week with the recent warmer spell.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest1372 on December 03, 2017, 05:37:23 PM
Is there anything special recommended that helps you get to 50+?
Tyre pressure kept high at 32 or 33, use the first quarter of the throttle pedal, ~never~ use the brakes, well... plan not to use them.  Constant speed on a dual carriageway is best, it takes 14x more energy to accelerate a mass of 1100kg from 65>75mph than from 0>10mph* that's just the mass - I'm not considering resistance caused by the drag.  So a constant 70 is much more efficient than variations averaging that speed.
--
TG

Ex,y=½(my2−mx2)
E0,10 10,995 J vs. E65,75 153,934 J
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest7277 on December 03, 2017, 07:34:09 PM
my 2003 jazz gets over 50mpg on motorways. Which has improved since i replaced all 8 spark plugs.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on December 13, 2017, 07:36:11 AM
A big drop in mpg this top up. Down to 49 mpg. However, I had only to fill up once in the last month, which means I have done a greater percentage of morning commutes and less longer journeys. Plus the weather has been so much colder. That also depresses the fuel efficiency.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: RScorpio on December 16, 2017, 07:27:18 AM
My MPG has dropped down even further from 44 to 41.5 - I have a CVT model through so perhaps economy will be on the lower side anyways. I also did have my heaters at full blast over the last few journeys, but did not realise this can have such a massive impact.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on December 16, 2017, 09:14:39 AM
CVT should give better mpg than a manual. I don't think the heater per se has a big effect. I think it is the weather that necessitates the heater that makes the difference.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: u587162 on December 18, 2017, 05:00:01 PM
my 2003 jazz gets over 50mpg on motorways. Which has improved since i replaced all 8 spark plugs.

How does changing the spark plugs improve performance?  Whats the cost of replacing them?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on December 18, 2017, 05:40:24 PM
my 2003 jazz gets over 50mpg on motorways. Which has improved since i replaced all 8 spark plugs.


How does changing the spark plugs improve performance?  Whats the cost of replacing them?

New plugs generally improve engine response and mpg because a good spark is required for best performance and as plugs wear out the gap increases and insulator gets coated up with carbon,  which can affect spark.  New plugs also reduce the demand on the ignition coil and ensure a longer life for that, the rear plugs rarely get replaced on the 8 plug GD iDSi engine and there are cases on this and other forums of rear coils failing due to much too large a gap on worn rear electrodes.

I got my last plugs for Jazz and Civic from Opie oils,  there are a lot of Chinese copies of spark plugs around - don't go too cheap on ebay  :-X

These are standard NGK plugs...  https://www.opieoils.co.uk/pv-78126-ngk-bkr6e-11-2756-standard-spark-plug-sparkplug-projected-centre-electrode-single-plug.aspx

But plenty of compatible plugs to choose from including Bosch Iridium at a great price if you want longer life between changes  (because of their long service life iridium plugs have a smooth nickel plated thread to stop them sticking in aluminium thread of the cylinder head)

https://www.opieoils.co.uk/c-2702-lookup-results.aspx?vehicleid=4676&variantlist=79644:167787%7E167788,78126:184608%7E184609,117581:828547,214077:0,214128:1258606%7E1258607,214010:0,213981:0,213998:0&yearFilter=2004
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on December 18, 2017, 06:29:27 PM
How does changing the spark plugs improve performance?  Whats the cost of replacing them?
I changed mine in the summer. 8 off NKG BKR6E-11 spark plugs  £14.98
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: sparky Paul on December 20, 2017, 12:20:06 PM
The plugs were supposed to have just been done on ours, not long before we got it, according to the wad of invoices. I have my doubts though, the rear ones especially don't look as though they have been disturbed for a while.

I found a set of NGK plugs for £11 delivered, they will probably be going in next service.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on December 20, 2017, 01:39:59 PM
http://www.scc-racing.com/racing-blog/warning-non-genuine-spark-plugs

https://www.driven2automotive.com/blog/how-to-spot-fake-denso-iridium-power-spark-plugs-2017/

https://thecounterfeitreport.com/product/400/Ngk-Spark-Plugs.html

http://www.globaldenso.com/en/products/aftermarket/plug/catalog/asia/pdf/P043.pdf

There are loads of fake Chinese copies of pretty much all branded products,  spark plugs are no exception.  Many fakes use steel for centre electrode instead of copper (copper takes the heat away quickly and dissipates it into cylinder head,  steel will eventually melt or excess heat will cause insulator to fail and drop into cylinder).

I am always careful to buy spark plugs from fairly reputable places like Cox motors or Opie,  shame to save a few quid on plugs (when they are not expensive anyway) and cause problems,  and if an insulator or electrode fails and drops into engine, oooops ££££'s.

A phrase my mate uses sticks in my mind 'you don't always get what you pay for, but if its too cheap its invariably sh!t3'
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on December 20, 2017, 07:04:32 PM
Buy from a reputable source. Not your Johnny Awthing shop.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: sparky Paul on December 20, 2017, 07:41:15 PM
I think mine are okay, they were from Halfords.

Halfords were clearing out the blister packs of 4 NGK earlier in the year, knocking the prices down until they were all gone. Some of the more obscure types ended up at a couple of quid a pack.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: owen on December 31, 2017, 01:23:16 PM
We have a CVT which gets used for short trips around London and driven with some enthusiasm.  Typically we see 35 MGP on the meter.  I've found that this is more or less the minimum fuel economy, no matter how hard it is driven it won't ever be less than 35 MPG.  I used to do some motorway work and could get around 55.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 05, 2018, 07:10:26 AM
Filled my tank again today and the calculated figure was 53.9 mpg. This isn’t very great, but I am unconcerned as I know I am only seeing random variation. For this I use SPC and Western Electric Rules.
I spent a good number of years working in industries where data gathering was a necessity and statistical analysis was priority. When I worked in the semiconductor industry I was first introduced to Western Electric Rules and how they are implemented to control that manufactured parts are in specification. When I worked in Lexmark, manufacturing ink cartridges, statistical process control was most important, and the control of the process was in the hands of the workers on the shop floor. Data is only of any use when it is fresh, and has to be acted on immediately. There is no point in manufacturing a nightshift’s product only for the engineer to come in the next morning, measure it, and find it is all out of spec. As an example, Lexmark would weigh sample bottles every half hour. The information is entered into an SPC chart, and from that a decision is made whether any changes need to be made to the process.
We worked to what are known as Western Electric Rules, a system implemented by Western Electric back in 1956. https://en.wikipedia.org/wiki/Western_Electric_rules It is these same rules I use to check on my fuel consumption figures, and decide if I am seeing a random spread or if I have an issue that needs looked at.
As an aside, the dashboard readout gave my mpg as 53.9. Remarkably close to the calculated figure.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: sparky Paul on January 05, 2018, 09:57:19 PM
Ours dropped to mid-40s mpg last week, accompanied by a hot front right hub.

Investigation revealed nothing much,  caliper sliders free enough, some dried out brake grease around the pads, which were fairly tight.  Cleaned up, greased and refitted pads, and slipped a bit of liquid silicone behind the piston dust cover. Seems okay now, no longer binding. We'll see how it goes... hope the mpg recovers!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 05, 2018, 10:37:15 PM
Assignable cause. Exactly what my SPC does for me!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: u587162 on January 08, 2018, 02:29:14 PM
my 2003 jazz gets over 50mpg on motorways. Which has improved since i replaced all 8 spark plugs.


How does changing the spark plugs improve performance?  Whats the cost of replacing them?

New plugs generally improve engine response and mpg because a good spark is required for best performance and as plugs wear out the gap increases and insulator gets coated up with carbon,  which can affect spark.  New plugs also reduce the demand on the ignition coil and ensure a longer life for that, the rear plugs rarely get replaced on the 8 plug GD iDSi engine and there are cases on this and other forums of rear coils failing due to much too large a gap on worn rear electrodes.

I got my last plugs for Jazz and Civic from Opie oils,  there are a lot of Chinese copies of spark plugs around - don't go too cheap on ebay  :-X

These are standard NGK plugs...  https://www.opieoils.co.uk/pv-78126-ngk-bkr6e-11-2756-standard-spark-plug-sparkplug-projected-centre-electrode-single-plug.aspx

But plenty of compatible plugs to choose from including Bosch Iridium at a great price if you want longer life between changes  (because of their long service life iridium plugs have a smooth nickel plated thread to stop them sticking in aluminium thread of the cylinder head)

https://www.opieoils.co.uk/c-2702-lookup-results.aspx?vehicleid=4676&variantlist=79644:167787%7E167788,78126:184608%7E184609,117581:828547,214077:0,214128:1258606%7E1258607,214010:0,213981:0,213998:0&yearFilter=2004

How often do they need to be cjanged and how would you know they need changing? 
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on January 08, 2018, 03:35:10 PM
my 2003 jazz gets over 50mpg on motorways. Which has improved since i replaced all 8 spark plugs.


How does changing the spark plugs improve performance?  Whats the cost of replacing them?

New plugs generally improve engine response and mpg because a good spark is required for best performance and as plugs wear out the gap increases and insulator gets coated up with carbon,  which can affect spark.  New plugs also reduce the demand on the ignition coil and ensure a longer life for that, the rear plugs rarely get replaced on the 8 plug GD iDSi engine and there are cases on this and other forums of rear coils failing due to much too large a gap on worn rear electrodes.

I got my last plugs for Jazz and Civic from Opie oils,  there are a lot of Chinese copies of spark plugs around - don't go too cheap on ebay  :-X

These are standard NGK plugs...  https://www.opieoils.co.uk/pv-78126-ngk-bkr6e-11-2756-standard-spark-plug-sparkplug-projected-centre-electrode-single-plug.aspx

But plenty of compatible plugs to choose from including Bosch Iridium at a great price if you want longer life between changes  (because of their long service life iridium plugs have a smooth nickel plated thread to stop them sticking in aluminium thread of the cylinder head)

https://www.opieoils.co.uk/c-2702-lookup-results.aspx?vehicleid=4676&variantlist=79644:167787%7E167788,78126:184608%7E184609,117581:828547,214077:0,214128:1258606%7E1258607,214010:0,213981:0,213998:0&yearFilter=2004

How often do they need to be changed and how would you know they need changing?

Standard plugs in i-DSi twin spark engine (8 plugs) change every 24,000 miles is recommended - Iridium type (4 plugs)  in VTEC engine (2008 -->>>) are every 70,000 miles.
 
If I had a GD that I was going to keep for a while I would be tempted to fit Iridium plugs to the rear positions and normal plugs in front - they would then be easy to change just the front 4 every 24,000 and the rear 4 every 72,000 (don't think extra 2000 miles would be a problem)..

If you don't know when plugs were changed I would change them anyway as they do affect performance and mpg.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 08, 2018, 04:11:28 PM
If I had a GD that I was going to keep for a while I would be tempted to fit Iridium plugs to the rear positions and normal plugs in front - they would then be easy to change just the front 4 every 24,000 and the rear 4 every 72,000
I had intended doing that. but was advised against it.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on January 08, 2018, 04:43:35 PM
If I had a GD that I was going to keep for a while I would be tempted to fit Iridium plugs to the rear positions and normal plugs in front - they would then be easy to change just the front 4 every 24,000 and the rear 4 every 72,000
I had intended doing that. but was advised against it.

Can't see a problem with it except up-front cost, iridium just keep the proper gap longer and give the coils an easier time because they need less voltage to give required spark.


IMHO Honda did not fit iridium originally because of extra cost.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: u587162 on January 08, 2018, 04:52:51 PM
I bought the car (2007 reg) with 95k miles on the clock in Xmas 2016.  Spent a few hundred cleaning up the car (new exhaust, CVT flush, just changed the EGR) and did a service in Jan 2017. Wife does about 2000 to 3000 miles a year and the car came with no service history so not sure when the plugs were changed.

How much would it cost for those iridium plugs on my car if change the 4(?).
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on January 08, 2018, 05:26:14 PM
I bought the car (2007 reg) with 95k miles on the clock in Xmas 2016.  Spent a few hundred cleaning up the car (new exhaust, CVT flush, just changed the EGR) and did a service in Jan 2017. Wife does about 2000 to 3000 miles a year and the car came with no service history so not sure when the plugs were changed.

How much would it cost for those iridium plugs on my car if change the 4(?).

If only doing low annual mileage hardly worth Iridium as normal plugs will last 8 years at 3,000 miles a year.

If you want iridium look at the lowest Opie oils link in my post that you quoted earlier.

You can get Bosch iridium for less than a fiver.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: MartinJG on January 08, 2018, 08:41:30 PM

I managed to get up to 49.3 on the gauge doing short mixed journeys during summer/autumn.  Now that we have moved into winter it has plummeted to 48.9 although it crept back up to 49 this week with the recent warmer spell.

Latest tank fill today. MPG down from 48.3 to 48.1 on the gauge and 42.2 real world calculation.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: sparky Paul on January 09, 2018, 01:05:58 PM
Sadly, I think my caliper needs further attention - it's getting warm again.  :(

The caliper, and what I could see of the piston, both look in good condition, so seal kit ordered and a full strip and rebuild is in order first... and a new flexi if that doesn't work.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Pauste9570 on January 14, 2018, 08:25:34 PM
42,8 (6.6l/100 km) driving mainly in the "city"... But I have very heavy foot
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 14, 2018, 09:46:25 PM
A heavy foot will certainly do that to your mpg. City driving takes a lot of finesse to return good economy.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: philiph on January 19, 2018, 08:47:06 AM
My 2005 got an actual of 48.08 MPG.
The board computer said 55.38.
(370 miles driven)

Did anyone else have such a big difference?
What could be the reason for such a big difference?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 19, 2018, 09:57:01 AM
Today I got 51.9 and the display said 53.9. Within 3.5%. Your error seems exceptionally big at over 15%.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on January 19, 2018, 01:54:04 PM
I've often wondered what causes the difference between computer mpg and actual. I'm fairly consistent at the computer being 10% out (it exaggerates my mpg by 10%). This was pretty much the same on previous cars I've had including a VW Golf.

But here we have a 15% and there are drivers who record a very small percentage difference. Does driving style have anything to do with it?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on January 19, 2018, 03:13:59 PM
I've often wondered what causes the difference between computer mpg and actual. I'm fairly consistent at the computer being 10% out (it exaggerates my mpg by 10%). This was pretty much the same on previous cars I've had including a VW Golf.

But here we have a 15% and there are drivers who record a very small percentage difference. Does driving style have anything to do with it?

I think driving style does play a part,  the fuel used data is gathered from ECU 'injector open times' and the miles traveled is gathered from speedometer.  I know the average MPG trip readout updates about every 10 seconds with a snapshot of the MPG at that time ( you can see this if you zero a trip and watch how often a new figure appears on the readout,  as the miles on trip increase it gets more and more sluggish to alter the MPG reading no matter how you drive, must be that any change in instantaneous MPG is averaged over greater mileage so makes less and less difference as trip miles mount up). If you are a particularly aggressive driver it makes sense that things can happen in between those 10 second updates that don't get recorded, but if you are a smooth careful driver the 'snapshots' and the time between snapshots would be more likely to be pretty much the same. 

Jocko is the most careful driver here so maybe he can comment on readout vs actual mpg he sees.

More likely explanation though is that the speedo normally reads 'fast' by up to 10% (by law it cannot read slow) so this could fool system that you have done more miles than you have actually covered,  so amount of fuel used spread over more miles is better MPG, and that is what the readout normally shows 'optimistic'.  Makes you think that trip and total mileage recorded by car is also 'optimistic' so that when you have done 110,000 miles you may only have actually done 100,000  :o

I reset one of the trips every time I fill up to get most accurate readout of MPG.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest4871 on January 19, 2018, 03:14:46 PM
Do you zero the computer at each refill? i.e. compare like with like.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 19, 2018, 04:17:10 PM
I agree with culzean (must be one of the few times :) ), driving style appears to make a difference. I notice a difference in accuracy depending on my driving style.
My Mk1 has the most basic computer, only showing the average mpg (I fitted a ScanGauge E to show instantaneous mpg) and I zero it every time I fill the tank. This works for me as I don't use the trip gauge for anything else, in fact I only ever move odometer off mpg when I am checking the mileage for a top up.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: John Ratsey on January 19, 2018, 09:35:36 PM
My 2005 got an actual of 48.08 MPG.
The board computer said 55.38.
(370 miles driven)

Did anyone else have such a big difference?
What could be the reason for such a big difference?
One possible cause of a big difference is that the fuel tank wasn't filled up as much at the start as at the end. This potential error will get smoothed out over time if you keep recording future fill-ups. However, the difference you are seeing represents 1 gallon (~4.5 litres) whereas any filling difference should be more than one or two litres.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: John A on January 19, 2018, 10:03:46 PM
With all the cars and motorbikes I've owned and checked against a GPS then the odometer tends to be spot on, even if the speedo is up to 10% out. My mk 2 Jazz has the most accurate speedo of all the cars I've driven recently, only a few percent fast.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 19, 2018, 10:27:09 PM
My speedo is the same. Very close to the GPS speed indicators on my Sat Nav and Dash Cam.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: MikeG1944 on January 20, 2018, 10:39:46 AM
My speedo is the same; I've never had a car with a speedo so accurate. Spot on when tested with the SatNav. Not even 1mph out! :)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Kenneve on January 20, 2018, 11:11:51 AM
It would seem that the Mk3 speedo is not as accurate as the earlier models, mine is approximately 2 mph optimistic throughout the normal speed range, as compared with the satnav

When the satnav is showing 30 mph the speedo is reading 32mph, with similar results at 50 and 70mph.
I tend to regard the satnav as the most accurate and this seems to be confirmed, by the roadside speed indicators where they flash up a warning, when you are over the limit.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: MartinJG on January 20, 2018, 12:45:18 PM
Size of tyres and tread can make a difference. As an extreme example, years ago I made the mistake of fitting a rear fat nobby tyre rear to my motorbike thinking it would give me more comfort in Australian conditions. It made no difference to comfort, the grip was terrible in wet conditions and the larger diameter acted like an extra gear ratio with the result that overall, I lost performance and MPG. 
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on January 20, 2018, 12:48:43 PM
It would seem that the Mk3 speedo is not as accurate as the earlier models, mine is approximately 2 mph optimistic throughout the normal speed range, as compared with the satnav

When the satnav is showing 30 mph the speedo is reading 32mph, with similar results at 50 and 70mph.
I tend to regard the satnav as the most accurate and this seems to be confirmed, by the roadside speed indicators where they flash up a warning, when you are over the limit.

Due to slight differences in tyre diameters and also for wear (although tyre wear would make it read 'faster' anyway) the speedo is by law (certainly construction regulations) 'optimistic,  otherwise,  with some police areas (like North Wales) having 'zero tolerance' for speeding you could be caught if your speedo was reading low.

https://www.theglobeandmail.com/globe-drive/culture/commuting/why-you-may-not-be-driving-as-fast-as-you-think/article11487709/

There are a lot of variables with tyres, and even inflation pressure can change diameter, but satnav does not need those fudge factors as it is independent of the vehicle it is used in.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 20, 2018, 01:45:15 PM
Yes, Sat Nav is spot on for speed, but remember, the display only updates at finite intervals, so when it is spot on if you are travelling at a steady speed, it is lagging if the vehicle is accelerating or braking.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on January 20, 2018, 01:46:36 PM
Interesting side issue here about wheel sizes and the effect on mpg. Buy a Jazz with bigger wheels and the CO2 goes up and the mpg down. Noticed this particularly when looking at the latest Jazz but also the Toyota Yaris. Get big wheels on the Yaris Hybrid and you are then liable for the London Congestion charge - get small wheels and you aren't. Small wheels 75 grams of CO2 - big wheels 82 grams

I am clueless on this and I know there are some clever people on this forum. My thinking is  - the bigger the wheel, the fewer times it will have to go round hence less fuel.

I'm embarrassed to ask this question but why is that?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 20, 2018, 01:57:07 PM
The bigger the wheel the fewer times it will have to go round - but the more effort that is required to turn it, hence marginally more fuel burnt.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on January 20, 2018, 03:13:30 PM
Interesting side issue here about wheel sizes and the effect on mpg. Buy a Jazz with bigger wheels and the CO2 goes up and the mpg down. Noticed this particularly when looking at the latest Jazz but also the Toyota Yaris. Get big wheels on the Yaris Hybrid and you are then liable for the London Congestion charge - get small wheels and you aren't. Small wheels 75 grams of CO2 - big wheels 82 grams

I am clueless on this and I know there are some clever people on this forum. My thinking is  - the bigger the wheel, the fewer times it will have to go round hence less fuel.

I'm embarrassed to ask this question but why is that?

https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=175

larger diameter tyres have more rolling resistance.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: John Ratsey on January 20, 2018, 05:37:39 PM

https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=175

larger diameter tyres have more rolling resistance.
Isn't the outer tyre diameter the same but the EX wheels are bigger and shod with lower profile tyres? Do the less flexible shorter sidewalls on the lower profile tryreshave more or less energy loss than the normal tyres? I can't figure out the answer from the explanation in that link.

I also wonder if the extra bells and whistles on the EX add to the weight which worsens the mpg. Are there also any extras which would worsen the aerodynamics?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest1372 on January 20, 2018, 05:54:27 PM
On the original Mk1 cars with alloy wheels were listed as having a worse mpg than steel wheel cars.  The rolling circumference / diameter was the same but they have a wider tread and therefore a greater contact patch.  Maybe compare a normal 26" x 1.75" bike tyre to a race bike at less than an inch wide, much much less resistance.

This phenomenon has been exploited by Volvo in the past with their V50 DRIVe fitted with ugly standard narrow low resistance wheels for testing / certification but outfitted by every dealer with smart alloys like other cars in the range.
(http://www.carenthusiast.com/volvo/volvo_c30_drive_2009_012_250.jpg)
--
TG
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on January 20, 2018, 08:36:18 PM

https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=175

larger diameter tyres have more rolling resistance.
Isn't the outer tyre diameter the same but the EX wheels are bigger and shod with lower profile tyres? Do the less flexible shorter sidewalls on the lower profile tryreshave more or less energy loss than the normal tyres? I can't figure out the answer from the explanation in that link.

I also wonder if the extra bells and whistles on the EX add to the weight which worsens the mpg. Are there also any extras which would worsen the aerodynamics?

On the Yaris, from what I can see, there are not that many extra bells and whistles between the Excel and the model one grade down - the Icon. You may get extras like sat nav but they are all on the infotainment type screen anyway. I wonder what would happen if you bought a Yaris with big wheels and changed them to small ones - would you then be able to claim exemption from the London Congestion Charge.

Not that I would ever be in that position but I reckon there would be lots of forms to fill in LOL.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: ondatony on January 24, 2018, 07:07:54 PM
I own a 2005 Jazz with 15" alloy wheels which I have owned for 10 years. All this time, I regularly got readouts of between 56 -61 mpg on the cars computer on a regular 30 mile, mainly motorway, journey. (The highest was 66 mpg). Just before Christmas I had the two front tyres replaced with the same size and make (Yokohama), and a new battery to replace the original one! Since then the computer readout has dropped to 47-51 mpg for the same journey. Odd??
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 24, 2018, 08:33:58 PM
New tyres make a huge difference to mpg. They are heavier, have more tread to distort (requires energy) and have a slightly larger diameter which means a taller gear. I noticed a big difference when I changed my front tyres. They will slowly improve until such time as they are due to be replaced!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on January 25, 2018, 12:54:29 PM
New tyres make a huge difference to mpg. They are heavier, have more tread to distort (requires energy) and have a slightly larger diameter which means a taller gear. I noticed a big difference when I changed my front tyres. They will slowly improve until such time as they are due to be replaced!

The ideal would be if they would stay at, say, 4mm forever!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: philiph on January 26, 2018, 08:59:18 AM
My 2005 got an actual of 48.08 MPG.
The board computer said 55.38.
(370 miles driven)

Did anyone else have such a big difference?
What could be the reason for such a big difference?

Yesterday the board computer said 58.85 mpg, m/g (miles per UK gallon) and the actual was 59.74 mpg, m/g (miles per UK gallon). 141 miles driven.

Much more accurate of the board computer. I changed my driving style successfully :-)

BTW: Is it US or UK MPG in this topic?
Thanks
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 26, 2018, 09:03:07 AM
I always use UK mpg. Most of the contributors here are UK or Europe.
That is a great mpg figure you achieved there. I cannot get anywhere near that at this time of the year.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on February 01, 2018, 07:27:42 AM
Once again, on-board display was pretty accurate. Display said 54.0 mpg and calculated figure was 53.5 (my sums) or 53.8 (Fuelly's figure).
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: philiph on February 02, 2018, 08:59:39 AM
This time I got 52,5 actual but the board computer was stating 57,6.

Don't know what I'm doing wrong :)

I do mostly highway with an occasional short city drive.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: MartinJG on February 02, 2018, 11:42:47 PM
The 'fibometer' was reading 47.7 on my last fill up but just over 40MPG on the real world reading. Mainly short journeys with a bit of everything @30-70 MPH.

Edit - The latest real world MPG calculation on top up yesterday is 44.36. Think the 'dip' in MPG was down to a 300 mile round trip on the motorway. The fibometer reading has been gradually creeping down over the winter period and appears to have bottomed over the last few weeks at @47.7. The average over the winter period is probably nearer the 43-44 mark. Apply the Honest John real world metric for the MK1 and that seems about right. I did a fibometer reset yesterday and it has jumped to around 49.5. So, it seems that 'fast trip' clearly dented the overall average MPG.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: sparky Paul on February 08, 2018, 03:10:37 PM
My 'fibometer' seems to have recovered its composure after fitting two new front brake calipers.

It's nice to see numbers starting with a '5' again, it was getting close to 40mpg at one point.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on February 08, 2018, 03:24:55 PM
Must have been grabbing then. Glad you got it sorted out.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: sparky Paul on February 08, 2018, 04:00:21 PM
Must have been grabbing then. Glad you got it sorted out.

Definitely been binding, offside was the worst. My experience with calipers is that the only permanent fix is a full overhaul with new piston & seals. I just can't be bothered at the moment, so new calipers it is. Pattern calipers aren't that much dearer than the repair kits anyway, and half an hour and they're fitted.

I'll have to change the fluid at some point soon too, it looks lousy - despite history & invoices to say it's been changed every two years. The colour of it tells me otherwise!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on February 08, 2018, 05:08:25 PM
I'll have to change the fluid at some point soon too, it looks lousy - despite history & invoices to say it's been changed every two years. The colour of it tells me otherwise!

My brothers mother-in-law had her car serviced regularly,  but when we checked brake fluid it looked (and smelled) as though it had never been changed and there was a deposit on bottom of reservoir. 

Truth is  who can you trust ?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: philiph on February 09, 2018, 06:12:08 AM
Onboard display 55,39.
Actual 52,31.

After not even two months of owning a jazz i Will definitly buy a jazz over and over again. Love it.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on February 09, 2018, 06:42:22 AM
After not even two months of owning a jazz i Will definitly buy a jazz over and over again. Love it.
I am of a similar mind. Hopefully my Jazz will see out my motoring years.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: sparky Paul on February 09, 2018, 09:59:48 AM
After not even two months of owning a jazz i Will definitly buy a jazz over and over again. Love it.
I am of a similar mind. Hopefully my Jazz will see out my motoring years.

Other half is the main driver of ours, she always liked the Jazz and absolutely loves the car. It was meant as a cheap stopgap, but I can see us replacing it with another when the time comes. Very practical little car, and well put together.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on February 16, 2018, 07:23:54 AM
Filled the tank up again this morning. The light wasn't near coming on, but I have an 80 mile trip tomorrow and ScanGauge was telling me I had enough left for 115 miles. Didn't want to chance it.
ScanGauge said I had got 50.2 mpg, dashboard display said 52.1 mpg and calculated figure was 51.9 mpg. Looks like my dashboard read out is fairly accurate with my driving style.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Basil on February 16, 2018, 12:38:29 PM
What's this ScanGauge then Jocko, what type do you have, what does it do and how easy is it to fit ?

Thanks.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on February 16, 2018, 03:22:11 PM
The ScanGauge E that I have, is a plug in unit that monitors instantaneous mpg and average mpg, among other things. It records data on a daily, previous day, current journey, this tank basis, and can display two out of many criteria such as rpm, coolant temp, intake air temp, and so on.
This is an example of the data I record on longer trips:
Average mpg: 50.9 mpg
Max coolant temp: 84°C
Distance travelled: 61 miles
Maximum revs: 4377 rpm
Max speed: 57 mph
Average speed: 28 mph


It plugs into the OBD II port, above the clutch pedal, and I have mine mounted on its Velcro, on the steering wheel binnacle.
(https://i.imgur.com/qV2N6DN.jpg)
It switches on automatically and is completely passive. Every time I fill up, I input the fuel added and the cost per gallon. After a few top ups the accuracy  gets pretty good.
It also reports any OBD codes and allows you to reset same.

Currently, Amazon are selling them for £92.20.
https://www.amazon.co.uk/ScanGaugeE-Ultra-Compact-Automotive-Computer/dp/B004SK5I46/ref=sr_1_3?ie=UTF8&qid=1518794320&sr=8-3&keywords=scangauge+e (https://www.amazon.co.uk/ScanGaugeE-Ultra-Compact-Automotive-Computer/dp/B004SK5I46/ref=sr_1_3?ie=UTF8&qid=1518794320&sr=8-3&keywords=scangauge+e)
 
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on February 16, 2018, 05:08:32 PM
Do you still do the brim to brim method as a back up Jocko?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on February 16, 2018, 06:52:08 PM
Do you still do the brim to brim method as a back up Jocko?
Oh yes, that is where the calculated figure comes from. This morning I put in 30.5 litres, which is 6.7 gallons. I use that and my odometer reading to come up with a calculated mpg figure. I always fill brim to brim and stop on the first cut off (Jazz is good for smooth filling). The calculated 6.7 gallons is fed into the ScanGauge, along with the price per gallon (the ScanGauge actually tells you how many gallons it reckons you have used and you + or - that figure), and that sets it up for the next tankful's figures.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: MartinJG on February 16, 2018, 07:28:54 PM
The ScanGauge E that I have, is a plug in unit that monitors instantaneous mpg and average mpg, among other things. It records data on a daily, previous day, current journey, this tank basis, and can display two out of many criteria such as rpm, coolant temp, intake air temp, and so on.
This is an example of the data I record on longer trips:
Average mpg: 50.9 mpg
Max coolant temp: 84°C
Distance travelled: 61 miles
Maximum revs: 4377 rpm
Max speed: 57 mph
Average speed: 28 mph


It plugs into the OBD II port, above the clutch pedal, and I have mine mounted on its Velcro, on the steering wheel binnacle.
(https://i.imgur.com/qV2N6DN.jpg)
It switches on automatically and is completely passive. Every time I fill up, I input the fuel added and the cost per gallon. After a few top ups the accuracy  gets pretty good.
It also reports any OBD codes and allows you to reset same.

Currently, Amazon are selling them for £92.20.
https://www.amazon.co.uk/ScanGaugeE-Ultra-Compact-Automotive-Computer/dp/B004SK5I46/ref=sr_1_3?ie=UTF8&qid=1518794320&sr=8-3&keywords=scangauge+e (https://www.amazon.co.uk/ScanGaugeE-Ultra-Compact-Automotive-Computer/dp/B004SK5I46/ref=sr_1_3?ie=UTF8&qid=1518794320&sr=8-3&keywords=scangauge+e)

Jocko

Surprised to see you maxing out at 4377 RPM with you being a low rev gear changer.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on February 16, 2018, 08:15:21 PM
Posted this under "Incredibly flexible little engine." on Thursday.
Had the car up to a heady 4377 rpm yesterday (ScanGauge E recorded). It is amazing what a quiet gearbox lets you do. Car pulls really well once you get it up there, but the indicated instantaneous mpg of 12.1 means I probably won't be making a habit of it!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on February 17, 2018, 03:27:14 PM
Did my usual Saturday run to visit my aging Mother-in-law. Tried keeping the speed up nearer 60 mph than my usual 50 mph and I seem to have got a better mpg figure. It is only the ScanGauge data but it looks a bit better.
Average mpg: 54.6 mpg
Max coolant temp: 84°C
Distance travelled: 76 miles
Maximum revs: 2909 rpm
Max speed: 58 mph
Average speed: 41 mph

As you can see my peak rpm is nearer my usual figure.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: ob13 on February 24, 2018, 09:39:12 PM
Can see why it gets called the fibometer! on my normal local running about the gauge consistently shows between 34 and 37 since i got it 2 months ago,which to be fair i thought was pretty reasonable. Today i filled up again having covered just under 200 miles and worked that out as 43.6 mpg(36.8mpg on dash).This was the first time i checked.Only a few less than i used to get out my diesel that i replaced so with unleaded being a few pence cheaper it must cost about the same.

The one time i went on a slightly longer run of about 25 miles each way i reset the dash and it showed about 46mpg i think, so hopefully this could be over 50.
Not been on a motorway trip yet but guessing with the autobox it will revving its nuts off to keep a decent speed and this mpg will drop a bit?


Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on February 25, 2018, 07:29:55 AM
I set mine when I fill the tank then leave it until the next time it needs filled. Think it is much more accurate this way, than resetting it every trip.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on February 25, 2018, 10:04:05 AM
Can see why it gets called the fibometer! on my normal local running about the gauge consistently shows between 34 and 37 since i got it 2 months ago,which to be fair i thought was pretty reasonable. Today i filled up again having covered just under 200 miles and worked that out as 43.6 mpg(36.8mpg on dash).This was the first time i checked.Only a few less than i used to get out my diesel that i replaced so with unleaded being a few pence cheaper it must cost about the same.

The one time i went on a slightly longer run of about 25 miles each way i reset the dash and it showed about 46mpg i think, so hopefully this could be over 50.
Not been on a motorway trip yet but guessing with the autobox it will revving its nuts off to keep a decent speed and this mpg will drop a bit?

The CVT actually pulls about 1000 revs less at 70 mph than the manual in fifth gear,  the i-shift will be at same revs as manual as it is an automated-manual box.

most people find the MPG display reads optimistic,  you are the first that I have sen that accuses it if being pessimistic.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on March 07, 2018, 08:30:33 AM
Light came on last night so I filled up this morning. Exactly 50 mpg, not bad considering the weather we have had and the fact I spent two days pootling about in the snow in 1st and 2nd gear. The "Fibometer" said 51.3 so that wasn't too bad. Only 2.6% error.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: sparky Paul on March 07, 2018, 10:07:47 AM
Ours is hovering around 48-49 on the fibometer currently, which I don't think is too bad, given the weather and the fact that a service is due... probably a little overdue now, I wasn't doing it in the freezing cold.

Fibometer figures seem to be born out by fag packet calculations on fill ups.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Lewo on April 06, 2018, 02:27:43 PM
Just done the first fill to click of pump tankful and was surprised that it worked out to 47mpg and 319 miles. That's driving around 12 miles with the low fuel light on.
Not that many motorway miles in that either and that was with Shell fuel, guessing it will be slightly less with supermarket fuel.
Happy though. :)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest7205 on April 14, 2018, 09:54:58 PM
43.7 over the last 6000 miles measured tank to tank. Usually about 45-46 according to the dashboard. Mixed driving. On a long run (I've done Sheffield to Durham and back today) taking it steady I'll see 53 on the dash, which I reckon translates to about 51 in real life.

Highly recommend fuelly.com if you like that sort of thing!

http://www.fuelly.com/car/honda/jazz/2004/tonedepear/699052
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on April 15, 2018, 09:08:00 AM
After filling up on Friday I went for an 85 mile run, yesterday. It was a mixture of town, country and motorway miles, and my ScanGauge returned 54.4 mpg for the day. The dashboard display for the tank had a way too optimistic 62 mpg, but I know that over the tankful that will peg back and arrive at a fairly accurate figure.
I am disappointing by my mpg at present, and a check of the wheel centres on my return yesterday showed the driver front a little warmer than the others (the rest were stone cold). I have set remedial action in progress.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: sparky Paul on April 15, 2018, 11:34:19 AM
Pesky brakes!  ;)

120 mile trip round trip yesterday, with a few miles of town driving at the other end. Fibometer reset at the beginning and reporting 62mpg on arrival and 59.5mpg on return.

Currently averaging around 48mpg locally, but still haven't got round to doing that service yet... been occupied with rather more important matters.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on April 21, 2018, 02:40:46 PM
After filling up on Friday I went for an 85 mile run, yesterday. It was a mixture of town, country and motorway miles, and my ScanGauge returned 54.4 mpg for the day. The dashboard display for the tank had a way too optimistic 62 mpg, but I know that over the tankful that will peg back and arrive at a fairly accurate figure.
I am disappointing by my mpg at present, and a check of the wheel centres on my return yesterday showed the driver front a little warmer than the others (the rest were stone cold). I have set remedial action in progress.
Had my brakes checked, and they were not sticking in the slightest. Today I did a 100 mile trip, in warm sunny weather. Immediately on my return I pulled the wheel trims and all 4 wheels were stone cold.
Crisis over!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on April 21, 2018, 03:15:15 PM
I think most people would be very happy with your mpg Jocko, especially on a 12 year old car. As a ball park you are over 12 miles per gallon ahead of me and I do try to drive carefully. It's my very short journeys that kills my mpg. I've noticed that there is a huge difference between 2 miles and, say, 4 miles, in mpg terms. Been looking at this using trip B.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on April 21, 2018, 06:47:53 PM
I cannot complain, really. It certainly beats the 29.8 mpg that my Volvo S40 returned, during my ownership.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on April 25, 2018, 05:41:54 PM
(https://i.imgur.com/qQ55wtl.jpg)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on May 03, 2018, 07:19:48 AM
A very much improved figure this top up. Brim to brim, 412 miles and 56.4 mpg. (Fibometer said 57.2 so not too far off) What was pleasant was I only had one top up during April, instead of the usual two a month. More down to when April's fell (mid month) as it is more a case of 23 per year than two per month.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on May 07, 2018, 01:10:48 PM
What a huge difference the warm weather makes to mpg. Today it is a dry and sunny 17 °C. I have done three short, cold start trips, all of them in town. According to my ScanGauge, for the 10.7 mile total, at an average speed of 15.8 mph, I have achieved 53.9 mpg. A week or so ago I was struggling to get near that on a long, gentle, run. Long may Summer (Spring?) continue!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on May 12, 2018, 01:42:48 PM
Another warm, dry day and I had my usual, two up, weekend  trip to visit my mother-in-law, south of Edinburgh. It is about 60% motorway/dual carriageway, the rest a mix of town and country driving. The roads were busy, but apart from a couple of slow moving queues mostly the traffic was moving steadily. I gathered my ScanGauge E data for the day, and was pleased with the results.

Average mpg: 59.0 mpg
Max coolant temp: 84°C
Distance travelled: 83.0 miles
Maximum revs: 4055 rpm
Max speed: 61 mph
Average speed: 37 mph

Considering most of my driving was at around 55-60 mph it is surprising how much the average is pulled down.
Country and town driving gives the best scope for improving your fuel efficiency. On the motorway most people get what they get. I don't like motorway driving, for that very reason.
I am doing no coasting, all in gear driving, making best use of DFCO and "a raw egg under the accelerator". I am being particularly brisk in accelerating up through the gears (over 4000 rpm is unusual for me!).
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on May 30, 2018, 04:46:34 PM
Today, as well as my usual taking my wife to her work, and picking her up after, we also had a trip into Edinburgh city centre. Most of the centre of Edinburgh is 20 mph now (very strictly enforced), which is just as well, seeing how many ancient cobbles I had to traverse today. Here is my data from my ScanGauge E:

Average mpg: 64.4 mpg
Max coolant temp: 84°C
Distance travelled: 61.3 miles
Maximum revs: 4158 rpm
Max speed: 58 mph
Average speed: 29 mph


Very pleased with that. I am now back to adding a little coasting in, where appropriate, and the warm dry weather is making a huge difference, though Fife is plagued with the early morning haar during weather like this.

(https://www.rettie.co.uk/site/uploads/cfp/pictures/p3509_00_img1069.jpg)

Some of the cobbles on today's route.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: JazzyJJ on May 30, 2018, 05:12:47 PM
Average mpg: 64.4 mpg

Impressive.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on May 30, 2018, 06:25:45 PM
The average speed says it all. Driving that slowly, in city driving, using anticipation to avoid braking where possible and switching ignition off at known long lights, makes a huge difference.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on June 02, 2018, 07:42:39 PM
Today my usual weekend trip was in warm still conditions, and according to My ScanGauge E, I averaged 67.1 mpg. And this was despite about 3 miles of 1st gear, stop start driving, due to a breakdown on the City Bypass. I am doing a bit of engine on coasting, when circumstances permit, and find that the car coasts great in this warm weather.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: sparky Paul on June 03, 2018, 10:10:04 AM
The Jazz really likes town driving, the gearing makes for great mpg tootling about.

Ours is averaging 50.7mpg on the fibometer after servicing, a mixture of driving, I'm happy with that.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on June 03, 2018, 10:56:22 AM
I find town driving allows the greatest scope for improving your mpg. With anticipation, turning the engine off at long lights, avoiding using my brakes, and trying to avoid the wheels actually stopping (keeping the car rolling can make quite a difference), I can make huge improvements. On the open road my mpg is no better than the next Jazz driver (unless he/she accelerates up behind traffic then brakes heavily).
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: philiph on June 08, 2018, 10:08:20 AM
Wow Jocko. Incredible MPG figures.

My average with this weather is about 57MPG.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on June 08, 2018, 10:28:07 AM
The number below my avatar is my overall average, summer and winter, for the entire time I have owned the car. This is recorded on Spritmonitor.de and includes fill ups from before I started driving with economy in mind.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: sparky Paul on June 08, 2018, 04:35:00 PM
Wow Jocko. Incredible MPG figures.

My average with this weather is about 57MPG.

Well, you can't really moan about 57mpg.

After a few slightly longer runs, ours is hovering around 52.5mpg on the fibometer, the service and Pento HP oil certainly seems to have made a positive difference.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on June 22, 2018, 07:34:25 AM
Filled my tank up this morning and my calculated mpg was 63.6 mpg, my second best ever. Both my ScanGauge (at 60.5 for the tank) and the on-board display (at 61.4 for the tank) were pessimistic. For the first time I used the Fuelly/peteo48 formula ( https://clubjazz.org/forum/index.php?topic=7808.msg61314#msg61314 Reply 170), and it gave me 33% urban miles and 67% interurban. Surprising, considering I always considered I did more urban driving, but probably fairly correct going on miles driven.
My ScanGauge data for the previous tank was:
Average mpg: 60.5 mpg
Max coolant temp: 84°C
Distance travelled: 488 miles
Maximum revs: 3544 rpm
Max speed: 68 mph
Average speed: 30 mph

Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: smilertoo on June 27, 2018, 10:51:07 PM
Using premium petrol i got it upto 41.5mpg from 39mpg, just before my clutch died. Hopefully a new clutch will increase my mpg instead of wasting half the power.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on June 27, 2018, 11:01:47 PM
That's about the improvement I saw when I tried Shell V-Power. Unfortunately, the extra cost didn't warrant using it on a regular basis.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest7784 on July 03, 2018, 07:38:16 PM
With my nearly 16-year-old, Auto box Jazz (bought new) and with careful driving I'm still getting 60+mpg, with BP Ultimate fuel…Only 50-53mpg with standard fuel, so as the percentage economy increase is larger than the percentage extra cost for the petrol it's worth paying for.

Still an incredible, workhorse car. And the greenest car is the new/used replacement you DON'T buy (as they say) so I intend keeping it until it craps out!  ;D
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on July 03, 2018, 09:14:37 PM
Welcome. That is very good mpg figures. I only saw 2-3 mpg difference, and here the price difference was 10p+ a litre, so there was no contest.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on July 13, 2018, 07:16:49 AM
Once again, a disappointing fill up at Morrisons. Apart from the fact that I was shopping there yesterday and didn't top up, then went in for petrol this morning and found it had gone up a penny a litre overnight! Lucky Friday the 13th.
What was disappointing was the fact that that my fibometer said 58.1 mpg for the tank, my ScanGauge said 59.8 mpg and my calculated figure was 53.2 mpg. That is roughly a 20% drop since my last top up, with almost identical drives and weather conditions.
As I said, disappointing.
I think I will try one of the less convenient to get to filling stations for a spell. See how it goes.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: smilertoo on July 20, 2018, 10:59:04 PM
well my new clutch claimed i was getting 48mpg....for a few hours, then it crept back down to 41mpg. I've since changed the oil and had the final four spark plugs changed; and i'm still at 41mpg. I'm out if ideas to try and improve it.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on July 21, 2018, 09:04:58 AM
Probably more to do with your driving habits, routes and anticipation than the car itself. I seldom ever use my brakes. In fact, unless I am approaching a downhill junction, I consider it a failure if I have to brake. As someone said elsewhere, "the brakes are for stopping and correcting errors".
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: philiph on July 21, 2018, 12:24:24 PM
390 miles.

56,5 real time at the pump
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on July 21, 2018, 02:14:17 PM
With my nearly 16-year-old, Auto box Jazz (bought new) and with careful driving I'm still getting 60+mpg, with BP Ultimate fuel…Only 50-53mpg with standard fuel, so as the percentage economy increase is larger than the percentage extra cost for the petrol it's worth paying for.

Still an incredible, workhorse car. And the greenest car is the new/used replacement you DON'T buy (as they say) so I intend keeping it until it craps out!  ;D

The price difference is 10 pence per litre on the branded fuels. It's only 5 pence per litre on Tesco and Sainsbury's high octane brews. Have you ever considered trying the supermarket stuff? Just interested.

Very impressive figures btw.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: RichardA on July 22, 2018, 12:00:16 PM
Welcome. That is very good mpg figures. I only saw 2-3 mpg difference, and here the price difference was 10p+ a litre, so there was no contest.

Same here, especially as I normally use a Sainsbury's petrol station in an area where there's also a Morrisons, ASDA, Tesco and x2 Esso stations within a few miles. The local Shell garage has much less competition so the price hike to use V-Power isn't worth it for the marginal mpg gains. Using Shell V-Power did however appear to make the EGR valve (?) issue less noticeable in stop/start traffic.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on July 22, 2018, 02:07:00 PM
Did an interim top up today, so I could do my annual anniversary audit. Unbelievable figure of 70.9 mpg for 234.2 miles. Short top ups are not the most accurate. Average for the past year (8,910 miles) worked out at 55.2 mpg.

I have stopped buying petrol at Morrisons. I crossed over town to Asda, so I will use them for a spell to see if I can avoid "iffy" top ups.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on July 22, 2018, 02:27:01 PM
Welcome. That is very good mpg figures. I only saw 2-3 mpg difference, and here the price difference was 10p+ a litre, so there was no contest.

Same here, especially as I normally use a Sainsbury's petrol station in an area where there's also a Morrisons, ASDA, Tesco and x2 Esso stations within a few miles. The local Shell garage has much less competition so the price hike to use V-Power isn't worth it for the marginal mpg gains. Using Shell V-Power did however appear to make the EGR valve (?) issue less noticeable in stop/start traffic.

I think the situation is that Jocko already drives carefully for maximum MPG.  so maybe higher octane would only make a small difference.  I drive 'fairly normally' and did notice that higher octane made enough difference to MPG and the smoothness of the engine to make it worthwhile,  and this was tried over many years of the same 80 mile round trip per day commute,  in all seasons and temperatures.   I don't do enough miles now to worry too much about MPG,  but still fill up every third or fourth tank with V power or similar.

I still think from experience that MK1 iDSi is capable of better MPG than later models if you want to drive it carefully,  so much for all the tech on later models promising better MPG.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: philiph on July 25, 2018, 11:19:12 AM
63,2 MPG

(380 miles, mostly highway)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on July 25, 2018, 12:49:18 PM
63,2 MPG

(380 miles, mostly highway)
That is exceptionally good. I struggle to get the numbers up on highway driving. Unless it is flat you have to keep the speed up to avoid the hills clawing you back, and there is not much you can do to make improvements. I like to get in behind a big truck (not too close just close enough to feel the benefit). I find that town and country roads offer the best opportunity to gain a few mpg, especially if you are familiar with the roads.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: philiph on July 25, 2018, 01:58:17 PM
Thanks.
Yes, sometimes I found myself being a truck. :-)


Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on July 30, 2018, 12:44:54 PM
Today I had a trip into Edinburgh city centre, in the tail of the morning rush hour, and back again an hour later. As usual, I recorded my ScanGauge information. The overall mpg for the 53 mile journey, was 65 mpg, but the figure for the return journey was actually 69 mpg. I find that the 20 mph zone, which is now the centre of Edinburgh, makes for good urban mpg. I pretty much sit in 4th gear, and just let it tootle along. For both parts of the short motorway section I managed to tuck in behind an HGV (not too close), and that always helps. Especially if, like today, I can get behind a fast HGV on the long incline from Rosyth to the A92 turn off. I fact, today I got a tow all the way to Cowdenbeath.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 23, 2018, 07:04:39 AM
Just as a matter of interest, I gathered the ScanGauge data after running my wife to work this morning. I averaged 61.8 mpg for the 3.9 mile round trip. This was from a cold start and the water temperature never quite got up to normal operating temperature. My average speed was 20 mph, a maximum speed of 33 mph and the maximum revs were 2512 rpm.
I have to reiterate that this was at 06:30, and despite all the miles being in town, with roundabouts and traffic lights, there was very little traffic. Conditions were dry and cool.
These figures were just those calculated by my ScanGauge, but it is pretty accurate as it re-calibrates at every fuel fill up and now has about 30 data points to work with.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on August 23, 2018, 09:34:15 AM
Interesting stats Jocko and quite revealing for me albeit I drive a 1.3 Mk3 CVT. I note that the trip was at 06.30 and the average speed was 20 mph.

I looked at the car's computer the other day. In 180 miles my average speed was 17 mph and that included some motorway driving but a whole lot more in dense traffic.

In fact, typically, at a refill, my average speed is about 15 or 16 mph. It shows how heavy traffic kills mpg.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 23, 2018, 10:04:35 AM
You can download the ScanGauge data by "Current journey", "Today", "Previous day", or "Tank". I have started noting the "Tank" at each top up, and my average speed is 30 mph over a tank full.  Does make a big difference.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Izzy on August 23, 2018, 05:48:23 PM
53.7 mpg on supermarket petrol usual local and one weekly motorway journey (88miles all in) cvt
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 23, 2018, 07:15:09 PM
53.7 mpg on supermarket petrol usual local and one weekly motorway journey (88miles all in) cvt
As you can see from the numbers below my avatar that is only 0.5 mpg off what I have averaged since getting the car. That seems to be a good achievable figure for the Mk 1.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 24, 2018, 07:18:33 AM
Filled the tank today. 391 miles, 6.7 gallons, 58.3 mpg. I better enjoy it while it lasts, as that will soon drop as the temperature drops!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on September 03, 2018, 01:23:59 PM
Another good top up. 443 miles at 57.5 mpg, calculated. My ScanGauge reckoned 57.4 mpg and the on-board was less than 2% optimistic, at 59.2 mpg.
Purely for convenience I went back to Morrisons, but wished I hadn't, as I slipped and fell on the forecourt. Feeling very sore now. When a 6 foot tall, 18 stone man falls all his length, there are inevitably consequences. Luckily I was still able to drive the short distance home.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: smilertoo on September 04, 2018, 02:58:26 PM
Jocko: do you have the spare wheel/jack/first aid kit in the back?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on September 04, 2018, 05:24:15 PM
Jocko: do you have the spare wheel/jack/first aid kit in the back?
I do indeed.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: sparky Paul on September 04, 2018, 07:09:45 PM
Purely for convenience I went back to Morrisons, but wished I hadn't, as I slipped and fell on the forecourt. Feeling very sore now. When a 6 foot tall, 18 stone man falls all his length, there are inevitably consequences. Luckily I was still able to drive the short distance home.

Hope you're not too damaged Jocko, take care!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on September 04, 2018, 07:29:11 PM
Thanks. I am not too bad today. Everything just merges in with my usual aches and pains!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on September 05, 2018, 08:05:07 AM
Purely for convenience I went back to Morrisons, but wished I hadn't, as I slipped and fell on the forecourt. Feeling very sore now. When a 6 foot tall, 18 stone man falls all his length, there are inevitably consequences. Luckily I was still able to drive the short distance home.

Ouch - hope you're  OK. 

Was it Diesel combined water that you slipped on ? A lethal combination more slippery than ice on Teflon.  I have had some fun in the past with that mixture,  on foot (garage forecourts ) in car and motorbike (on junctions and islands). If it was some substance on the floor they are liable.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on September 05, 2018, 09:29:40 AM
I don't think it was anything other than my slippy shoes and the wet forecourt. I was between the shop and the pumps when I went down. Shoes went straight in the bin when I came home. It was my own fault. I knew the Clarks shoes were slippy in the wet, as I have skidded about in the past. I stopped wearing them in the wet for that reason. It was dry when I put them on and when the rain started I should have changed them. The soles were worn smooth, but they were so comfortable (like wearing slippers), that I hung on to them.
I am none the worse for wear this morning. Thanks.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest7934 on September 06, 2018, 07:58:18 PM
Hi all, new member with an '03 1.4 SE manual, best yet is 56.6  :)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on September 06, 2018, 08:22:01 PM
Hi, Andy. That's good numbers. What do you do to get good mpg?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest7941 on September 10, 2018, 03:38:35 PM
Mine’s around 46mpg  Any advice what needs to be change and check? I just bought this car.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: VicW on September 10, 2018, 04:04:15 PM
Welcome.
Is that figure from the on board read-out which reads about 5% high?
46mpg isn't too bad, one of the biggest influences on fuel consumption is your right foot plus type of use. Is most of your mileage in town or on main roads?
Regular servicing is essential for good fuel consumption,correct tyre pressures and, of course, the general health of the car.
Does the car have a good service history?

Vic.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on September 10, 2018, 07:04:51 PM
Welcome to the forum. My first couple of fill ups were around about that figure, but once I got used to the car the numbers started to go up. The dashboard display is reasonable up to a point, but only over a complete tankful. I find mine is about 2 - 3% optimistic. The best bet is to calculate the figure. Fill your tank, note the odometer reading, drive until tank is nearly empty, then fill tank back up. Calculate from litres to fill the tank and miles covered just what mpg you are getting. You can use a site like SpritMonitor https://www.spritmonitor.de/en/ (https://www.spritmonitor.de/en/) to calculate and store your numbers.
How you drive makes a huge difference to your mpg. Every time you use the brakes you have wasted petrol getting to that speed. Anticipation, and lifting off early, saves petrol. I also keep my tyre pressures up. I run at 35 psig, front and rear.
If you have just got the car, unless you know otherwise it is a fair bet that the rear plugs haven't been changed for a spell (i-DSi has 8 spark plugs Dual Spark ignition).
Here's wishing you well with your new car. The Jazz is a great little machine.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on September 10, 2018, 09:48:03 PM
Just picking up on your onboard computer being 2 to 3% optimistic Jocko. I think that reflects your smooth driving style. I've noticed the computer is more accurate on long journeys than it is in my usual round town in traffic routine. Mine can be 10% out down to 5% on tanks reflecting a long journey.

Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: ob13 on September 19, 2018, 08:06:36 PM
The first few months with my car i experimented a bit and noticed a huge difference between proper garages eg shell/esso and supermarket fuel.I now pay the extra 10-15 pence or so a gallon and have good fuel everytime.

Last Saturday i drove from my home in Dorset via somerset to pick a mate and up to huddersfield and back in a day,filled up when we got there having driven nice and steady and with no traffic probs and had got over  53mpg.
 The plan worked perfectly and gave me a combined 45.5mpg over the whole trip having driven quicker home!

520 miles in a day it was and is the furthest i have driven for years and this little car really does continue to impress me,great little car!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on September 19, 2018, 08:12:49 PM
I now pay the extra 10-15 pence or so a gallon
You are lucky you only have to pay 10 - 15 pence per gallon. I have to pay that extra per litre.
I found I got one or two mpg better using Shell (not the most recent time though), but there was no way I could justify the extra cost.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: ob13 on September 19, 2018, 08:23:35 PM
or maybe we are unlucky the supermarkets dont go cheaper? i chuck their diesel in my vw van no problem!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on September 19, 2018, 08:35:15 PM
or maybe we are unlucky the supermarkets dont go cheaper?
That may well be the case. I pay £1.267/litre at the supermarket and £1.399/litre from the Shell station. The supermarket price is up a couple of pence per litre just now, as the big Asda filling station is closed for a huge refurbishing programme. The other supermarkets don't have much competition!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: ob13 on September 19, 2018, 09:26:48 PM
bit of both then,supermarkets are £1.309  and if i go to right garage i can get esso at £1.329  some are much higher!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on September 20, 2018, 10:58:50 AM
Filled the tank this morning. I was in two minds whether to stretch it out until Monday, but I have my 100 mile trip on Saturday and I was going to the supermarket anyway, so I just filled up. Petrol back down to £1.257/litre.
For my 324 miles I managed a calculated 54.2 mpg. A bit disappointing, but the weather has deteriorated over the past month and I have had a new tyre sapping the energy. Add to that the fact my average speed for the tankful was 25 mph and I suppose I should be fairly pleased with the numbers.
The on-board computer calculated the tankful at 54.8 mpg.
The ScanGauge E worked it out at 53.9 mpg, so all pretty close to each other, but as usual the ScanGauge is closer than the on-board.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Paul22118 on September 20, 2018, 10:34:14 PM
Did a very long and mixed road journey last week and my Dec 09 Jazz auto returned 58mpg,
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on September 21, 2018, 06:45:53 AM
Great figure. The Jazz is a frugal machine, treated properly.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: philiph on September 21, 2018, 03:43:29 PM
Last fill about 51MPG.

But I was mostly moving furniture with my wife.

Great little car for this kind of stuff.

Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest7946 on September 25, 2018, 12:06:43 PM
56mpg highway in a 2002  1.5ltr
51mpg around town
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on September 25, 2018, 12:13:03 PM
Those are good numbers. You don't get the 1.5 here in the UK. Only available from 2018 models.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest7946 on October 04, 2018, 12:38:57 AM
Heres a pic of the best ive gotten so far
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on October 04, 2018, 06:08:10 AM
They always tell us everything is upside down in Australia, but I never believed it until I saw that photo!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest7946 on October 04, 2018, 06:57:59 AM
I dont know why it did that but adds to the fun maby thats why economy is better its all down hill lol
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: bus_ter on October 12, 2018, 12:08:02 PM
I thought it was about time to make an accurate measurement.

From the best part of a full tank (brim to brim), my stats:

Fuel Used: 32.12L
Mileage:    343.5m
Real MPG = 48.6MPG (UK Imp Gal)

Car gave me 50.4MPG so over estimating by 1.8MPG which is not too bad.

Car is a 2006 1.4 with 80K, recently serviced including all 8 spark plugs.
Driving was very mixed over this tank (short, long, urban, motorways etc)
Fuel is Sainsbury's Supermarket 95RON

EDIT: Reading above it seems I'm getting a little less than others, and my car reading is a bit further off than others. I don't think either is enough to be concerned about.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on October 12, 2018, 01:55:02 PM
Not too bad for this time of year. and it is only over one tankful. My worst figure is 46 and my best 70.9 so there is a huge variance to be had. I drive to achieve the best mpg I can, and my average over my ownership of the car is the number below my Avatar, over there on the left.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: RichardA on October 14, 2018, 12:36:24 PM
Used Shell V Power a few weeks back, just filled up and got a return of 411 miles trip and 50.14mpg. And that was with two trips keeping the revs at 3,000rpm and using third or fourth gear on country roads as mentioned in another thread, to give the Jazz a clean out. But a tank full of V Power did cost me £10 more than Sainsburys.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on October 14, 2018, 12:53:02 PM
Like you, I found a marginal improvement using V-Power, but the improvement didn't warrant the extra cost so I reverted back to supermarket blend.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest4871 on October 14, 2018, 12:57:08 PM
A very impressive table. A pence per mile column might also be interesting?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: istvantamas on October 26, 2018, 08:43:14 AM
2004 1.4dsi 151k miles

47,5-54,5mpg according to the comp.

Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on October 30, 2018, 10:31:39 AM
I just bought a 2008 Jazz 1.4 Sport (GE3) with 106k miles.

I topped up and reset the mpg meter.
After 120 miles of mostly town driving the dash said 43.2 mpg, toppimg up again I made it 38.5
Another 230 miles including more motorway and a new air filter the meter showed 45.7 but I made it 42.4

So a service is in order when I can get to my brother's workshop.

I don't know why the computer should be exaggerating so much.

I notice it's short runs from cold that really kill the mpg so I might try some 0-20w oil.

UPDATE
Fairly sure I have the EGR valve problem. I bunged some redex in, no change. From reading here I tried an 'Italian tune' revving well over 3500 - very alien to the way I drive. After the first try I saw 50+ for the first time, but then back to the 40s. Just done it again. Only for a few miles of dual carriage way. I reset the mpg A few more miles at a steady 50mph and it seemed to be heading for 64mpg. With a final couple of miles on A roads and traffic free town I ended at 68. On the way back a steady 45 got me over 70mpg.

So the carb cleaner and gasket are on order. Many thanks I wouldn't have imagined it could make such a difference.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: smilertoo on November 10, 2018, 09:35:31 PM
I cleaned the EGR valve but the benefit was very short lived, does that mean i need a new valve or should i try and clean the entire EGR system and not just the valve?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on November 11, 2018, 10:40:50 AM
I wouldn't worry too much about the computer reading. It's within the range I've experienced over 3 Jazzes now. My recent fill was an actual 39.2 and a recorded 43. I've got to the stage where 4 mpg over optimistic is a reasonable bench mark. I record mine faithfully on Fuelly.com on the brim to brim method. To be honest that's because I'm a bit OCD about these things. I've often thought a quick check of the computer, knock off 4 mpg, and I'd be pretty much bang on.

I have noticed that, on long journeys, the percentage that the on-line computer is out is less. There are, on this site, people with the technical know how to explain this.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on November 11, 2018, 10:43:15 AM
Good question smiler. There is a link on one of the EGR threads here to a YouTube clip showing how to clean the pipework from the manifold. It looked straightforward.

I haven't done mine yet, I'm still waiting for the gasket to arrive.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on November 11, 2018, 10:50:26 AM
Thanks Peteo48. I have started a fuel mileage record.

That said the display is useful as a guide to what helps improve economy. For instance there's a long hill I often use here and I wonder if it's best to go up it in fourth or fifth.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on November 11, 2018, 11:44:44 AM
Good question smiler. There is a link on one of the EGR threads here to a YouTube clip showing how to clean the pipework from the manifold. It looked straightforward.

I haven't done mine yet, I'm still waiting for the gasket to arrive.

The only purpose of the EGR is to cool combustion at high revs by allowing exhaust gas into inlet manifold ( to reduce oxygen in the ingoing charge ) this reduces the nitrogen oxides in exhaust.  What does the damage to performance is when valve is open ( stuck ) at revs below 3000, this can cause lumpy running, lack of power and stalling. Even when it is working normally it reduces performance at higher revs, it  is better for performance if the valve never opens, but not so good for environment.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on November 11, 2018, 12:25:56 PM
Just thought I'd check my mpg as measured by the computer. On trip B - which I have kept at the same setting since I bought the car - it is showing an overall mpg, over around 1800 miles, of 48.4. The actual is 44.1 so around 10% out.

The 4 mpg figure almost seems a constant with my Jazzes. The best ever mpg I had in my last Mk2 Jazz was 56.2. I remember that the computer showed a tad over 60 mpg. In this case a smaller discrepancy in percentage terms but still 4 mpg!

A bit like that "the answer is always 42" thing from Hitch Hikers Guide to Galaxy (think it was that).
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: John A on November 11, 2018, 12:38:15 PM
A bit like that "the answer is always 42" thing from Hitch Hikers Guide to Galaxy (think it was that).

What's the answer to life, the universe, everything ?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on November 12, 2018, 08:12:17 AM
Fair point culzean. What I was  thinking was if the pipes from the manifold are mucky then when the EGR valve does open more crud might be getting in again.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on November 14, 2018, 11:30:43 AM
Did the EGR yesterday. Good job as there was no gasket  :o. No massive difference in mpg (45.7 by the comp after a few shortish urban trips) but seems to be a bit smoother to drive.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on November 14, 2018, 12:29:11 PM
Did the EGR yesterday. Good job as there was no gasket  :o. No massive difference in mpg (45.7 by the comp after a few shortish urban trips) but seems to be a bit smoother to drive.

Did you zero the trip before test drive with EGR fixed ? The mpg display is very sensitive when trip is reset, but will hardly change when 100+ miles on trip no matter how you drive. This is because mpg computer is averaging any instantaneous changes in mpg over a larger number of miles.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on November 14, 2018, 01:27:50 PM
Yes I zeroed the trip so it is an average over a small mileage (about 30 miles).

Which reminds me. I tried zeroing it before two trips up that mile long hill I mentioned. Not going above fourth gear it showed 33 mpg at the top. Keeping in 5th all the way 35.something. I was lucky with the traffic and was able to maintain the 40 mph limit both times. So 5th is better even though my foot is a lot further down on the pedal.

Reading around since I understand it's to do with BSFC (brake specific fuel consumption) and possibly lower pumping losses with the throttle open. But then as we said when I was studying physics an ounce of observation is worth a pound of theory.
(Yes it was a long time ago, though a gram being worth a kilo isn't beyond the realms of possibility.)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on November 14, 2018, 01:48:32 PM
Pumping losses ( pistons pulling against a throttle butterfly ) are a problem with petrol engines but not diesel ( diesel engines do not have a throttle as such but vary the amount of fuel injected to vary the power).   When the Civic 8th gen > ( and MK3 Jazz ) go into 'atkinson mode at low revs Honda do some magic by holding the throttle butterfly open and inlet valves open on the 'compression' stroke to pump some mixture back into inlet manifold,  lowering the compression ration and power output.  This reduces pumping losses.  The great hope for smaller engines with turbo is that the throttle would have to be opened more, giving reduction in pumping losses,  but the gains never materialised and the nitrous oxide levels went up over larger normally aspirated engines ( back to the drawing board )...
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on November 19, 2018, 10:26:29 AM
Did a couple of 100+ mile mostly motorway trips this weekend. After the first mpg showing over 48. Fairly happy, then I found the tyres were between 24 and 28 psi. With correct pressures I got home showing 50.4 mpg. That's cruising between 60 and 70.

Seems all's well with my Jazz  :D
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest7979 on December 05, 2018, 09:47:45 PM
Starting to think i have a problem, struggling to keep it at 41mpg and regulary get 39mpg.
14-20mile round trip daily with some traffic but daul carrige ways mostly.
Would the egr be worth cleaning?
Tyre pressures are good.
Only had the car 3 months and was "recently serviced" before i brought it but have no proof so its on my to do list asap. Might go buy parts tomorrow after work and do it the weekend.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: superb on December 07, 2018, 07:28:51 AM
Mid to high 30's, which I thought was pretty low as my commute is mostly A roads. Checked tyre pressures and they were all around 10-15 psi which probably explains part of the mpg and weird steering feel.

Gave it a major service last weekend (all filters, oil, sparks, brake fluid) and according to the computer I got 46mpg from this tank. 2007 1.4 se with 129k miles.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on December 07, 2018, 07:47:30 PM
Mid to high 30's, which I thought was pretty low as my commute is mostly A roads. Checked tyre pressures and they were all around 10-15 psi which probably explains part of the mpg and weird steering feel.

Gave it a major service last weekend (all filters, oil, sparks, brake fluid) and according to the computer I got 46mpg from this tank. 2007 1.4 se with 129k miles.

How did pressures get that low ? You may well have damaged sidewalls running them at that low pressure as sidewalls can flex way too much.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest7979 on December 08, 2018, 12:08:08 AM
Just to keep this updated.
Cleaned my egr valve and pumped my tyres up (mid 20's) and my dash currently reads 51mpg....huge dofferance. It didnt even look that dirty. Seems to pull off smoother aswell which is a welcome bonus
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: superb on December 10, 2018, 01:19:18 PM
Mid to high 30's, which I thought was pretty low as my commute is mostly A roads. Checked tyre pressures and they were all around 10-15 psi which probably explains part of the mpg and weird steering feel.

Gave it a major service last weekend (all filters, oil, sparks, brake fluid) and according to the computer I got 46mpg from this tank. 2007 1.4 se with 129k miles.

How did pressures get that low ? You may well have damaged sidewalls running them at that low pressure as sidewalls can flex way too much.

They wouldn't have got damaged at that PSI in a short space of time. The car was sat for almost a year before I bought it.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on December 10, 2018, 01:51:29 PM
Mid to high 30's, which I thought was pretty low as my commute is mostly A roads. Checked tyre pressures and they were all around 10-15 psi which probably explains part of the mpg and weird steering feel.

Gave it a major service last weekend (all filters, oil, sparks, brake fluid) and according to the computer I got 46mpg from this tank. 2007 1.4 se with 129k miles.

How did pressures get that low ? You may well have damaged sidewalls running them at that low pressure as sidewalls can flex way too much.

They wouldn't have got damaged at that PSI in a short space of time. The car was sat for almost a year before I bought it.

If the car hit a pothole with the tyres at that pressure damage is inevitable,  it is surprising how quickly sidewalls can be damaged by heat buildup due to excessive flexing - I guess you have never experience a blowout, well there is always a first time  :o
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: machedon on December 22, 2018, 09:23:02 AM
Hi there
My car is doing like 29-31 on dual carriageway and 40-43 on motorway at 70miles constant
Tire pressure is k
Before I Service it it was doing 36 on dual carriageways now it went allot down
I always use shell vpower.
It has only 41000 miles
What can be the problem?
It is a honda jazz 1.4 idsi sport auto
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on December 22, 2018, 11:00:09 AM
The cold weather can be a massive factor at this time of year. As you can see from my avatar my average is 43.8 on a Mk3 but, over the last 90 miles, the computer is showing 35 which is probably a genuine 32/33.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: machedon on December 23, 2018, 09:52:02 AM
Tks.
So should i relax i think.
Is my first car and i was woried a bit.
I think i am going to try the regular petrol from shell not the vpower.
Do ypu guys think is alright for this car?

Love my Jazz
 8)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: MicktheMonster on December 23, 2018, 10:24:08 PM
Any petrol is fine mate, no need to worry, some do have additives or higher RON rating (measure of the concentration of energy in the fuel) that your car may, or may not, run better on, some cars will show an increase in performance and some won't, it's a bit of trial and error to find one you are happy with, none of them will harm your car.

I generally buy supermarket petrol and have done for decades as it is generally cheaper (and Morrisons is the only full time petrol station in my town), I have never had any issues as a result of using this so I can only assume it is all fine or half the town would have broke down cars.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Kenneve on December 24, 2018, 09:40:53 AM
I to used to run on Supermarket fuel many years ago, whilst running a Landrover Freelander.
At one point, I reported an engine issue to my dealer and was asked what fuel I was using.
They recommended  I change to one of the well known brands, which i did, it solved the problem and I found I got better MPG, which more than paid the increase in costs. Currently running on BP regular.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on December 24, 2018, 10:45:27 AM
Any petrol is fine mate, no need to worry, some do have additives or higher RON rating (measure of the concentration of energy in the fuel) that your car may, or may not, run better on, some cars will show an increase in performance and some won't, it's a bit of trial and error to find one you are happy with, none of them will harm your car.

I generally buy supermarket petrol and have done for decades as it is generally cheaper (and Morrisons is the only full time petrol station in my town), I have never had any issues as a result of using this so I can only assume it is all fine or half the town would have broke down cars.

Higher octane fuel ( higher research octane number ) actually has less energy than lower octane, it has more additives and less 'fuel' to enable it to be harder to detonate, hence it can stand the heat of higher compression ratio ( feel the end of a bicycle pump when you have inflated a couple of tyres ) without prematurely exploding ( exploding before the spark tells it to ).  It has less total energy than lower octane but because the ignition point can be controlled better the engine can burn it more efficiently.  When the anti-knock sensors on an engine detect the sound and vibration signature of knocking or pinging the ECU retards the point on ignition ( fires the spark later in the piston stroke ) to limit the knocking ( which is actually trying to reverse the piston movement and send it back the way it came up rather than go through TDC and then push it down the way it was going ).  Retarding the ignition point means the engine produces less power.

As the spark ignites fuel and it starts to burn and the flame travels away from plug, the pressure in the chamber increases and with lower octane this can cause remaining mixture to ' pre-ignite' in an uncontrolled way causing knocking, so to stop knocking the spark is ignited later in the stroke by ECU, this drops engine power, with higher octane with less tendency to pre-ignition the spark can be advanced to fire earlier in the stroke, this gives fuel more time to burn properly in a controlled way, extracting more power from the compressed mixture. So even though the anti knock additives in higher octane reduce the energy content of fuel, they allow it to burn and be used more efficiently by the engine, Honda Jazz is around 11:1 compression ratio and although some tricks like spark plug being in the centre of combustion chamber and the actual shape of the chamber being designed to give even combustion there are limits to preventing knocking.  My motorbike with about same CR as Jazz has twin spark plugs ( like the Jazz GD has) to get better controlled of mixture combustion.

Modern ECU will listen to the knock sensor and advance the ignition until it hears knocking and then back it off a little,  with higher octane fuel the ignition will be more advanced before knocking is detected and this means engine can produce more power.  Your are most likely to get knocking at lower revs on a hill when the engine is 'slogging' (so ECU will retard timing just when you need the power more).
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on December 24, 2018, 11:16:35 AM
Interestingly the Compression Ratio on the Mk3 is 13.5:1 - higher than the MK1 or MK2. I've often wondered if this is a possible reason for using higher octane fuel.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on December 24, 2018, 01:30:48 PM
Interestingly the Compression Ratio on the Mk3 is 13.5:1 - higher than the MK1 or MK2. I've often wondered if this is a possible reason for using higher octane fuel.

The mk3 is direct injection and the fuel can be injected during the burn and this prevents pre ignition effect, and means the fuel / air mixture can be a bit leaner as well.  The direct injection system was designed to be able to use higher CR and not have knocking because the fuel mist is injected near the spark plug,  IIRC The Mazda sky active DI system has an even higher CR of about 16:1.

The bottom line is that DI do not need higher octane fuel to prevent knocking, which is dealt with by the mechanism of the DI system, the DI injectors work at much higher pressure than normal port injection ( the mk3 has an electric lift pump in the tank and an engine driven fuel pump for the high pressure). DI injectors have the solenoid replaced by a piezoelectric mechanism to work at much higher speed to enable the extremely precise timing of injection.

http://blog.jepistons.com/gdi-gasoline-direct-injection-the-future-of-high-perf-engines

https://www.theengineer.co.uk/issues/24-october-2003/perfect-piezo/
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: MicktheMonster on December 24, 2018, 02:46:40 PM
Good stuff, I stand enlightened (well... As far as I can understand/follow it anyway).

Thanks.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest4871 on December 24, 2018, 05:17:45 PM
Interestingly the Compression Ratio on the Mk3 is 13.5:1 - higher than the MK1 or MK2. I've often wondered if this is a possible reason for using higher octane fuel.

The mk3 is direct injection and the fuel can be injected during the burn and this prevents pre ignition effect, and means the fuel / air mixture can be a bit leaner as well.  The direct injection system was designed to be able to use higher CR and not have knocking because the fuel mist is injected near the spark plug,  IIRC The Mazda sky active DI system has an even higher CR of about 16:1.

The bottom line is that DI do not need higher octane fuel to prevent knocking, which is dealt with by the mechanism of the DI system, the DI injectors work at much higher pressure than normal port injection ( the mk3 has an electric lift pump in the tank and an engine driven fuel pump for the high pressure). DI injectors have the solenoid replaced by a piezoelectric mechanism to work at much higher speed to enable the extremely precise timing of injection.

http://blog.jepistons.com/gdi-gasoline-direct-injection-the-future-of-high-perf-engines

https://www.theengineer.co.uk/issues/24-october-2003/perfect-piezo/

Am I right in thinking this does not apply to the Mk 2?

PS Culzean - Many thanks for all your posts in 2018 (and before!). You are an inspiration to all of us who listen to your sage advice. A Merry Christmas to you and yours.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 18, 2019, 07:30:54 AM
Just filled up this morning. It wasn't a huge fill up but as I have a trek into Edinburgh this afternoon I thought I had better fill up, just in case. I had covered 325 miles since my last top up, fill took 6.2 gallons, returning 52.4 mpg.
Considering we are now into the middle of January I am really pleased with that figure. About 40% of my driving was around town, but I think the, so far, mild winter we are experiencing helped a lot. It is so mild here that the gorse is starting to bloom, and in some spots has been blooming since just before Christmas.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on January 18, 2019, 08:34:08 AM
Impressive Jocko.

I do wonder if the difference at lower temperatures is not so much to do with changes in the fuel and air but rather to the sensors in the exhaust taking longer to get up to working temperature. That might account for the way when I have to do very short trips my mpg plummets.

Anyone know anything about this?

CORRECTION
I found out the sensors include heaters to regulate their temperature so I was talking out of my hat, who would have guessed  ::)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 18, 2019, 10:07:26 AM
I get fairly good mpg on my short hops, it is the first 10 miles of longer trips which depress my mileage. I have my heater set to cold, constantly. The only time I put the heater on is after the blue light goes out on longer trips. I have noticed, that on a cold day, if I put the heater on as soon as the blue light goes out, it often comes back on for a brief spell.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: smilertoo on January 18, 2019, 10:30:44 PM
Im hovering at 38.2, possibly because its all town driving except a small hop onto the M8 then off one junction later.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest4871 on January 18, 2019, 10:47:37 PM
Just filled up this morning. It wasn't a huge fill up but as I have a trek into Edinburgh this afternoon I thought I had better fill up, just in case. I had covered 325 miles since my last top up, fill took 6.2 gallons, returning 52.4 mpg.
Considering we are now into the middle of January I am really pleased with that figure. About 40% of my driving was around town, but I think the, so far, mild winter we are experiencing helped a lot. It is so mild here that the gorse is starting to bloom, and in some spots has been blooming since just before Christmas.

I have the feeling that the basic specification for petrol changes from summer to winter to summer and is therefore seasonal as well.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 19, 2019, 10:23:42 AM
I have the feeling that the basic specification for petrol changes from summer to winter to summer and is therefore seasonal as well.
Possibly, but I know that the car coasts further in the summer than in the winter. On my regular trips I do elongated gear changes. By this I mean that as I approach a junction or roundabout, instead of changing down right at the hazard I will select neutral, 50, 60, 100 yards early, and coast up to the point where I select the gear for the hazard. This saves me having to brake. I know exactly when to select neutral to arrive at the hazard at the required speed, but in the winter these points are considerably shorter than in the summer.
I think it is down to the tyres being cold and hard, the transmission cold and stiff, possibly even the road surface (there is a huge difference between wet and dry tarmac as well).
It takes at least 10 - 15 miles of winter driving before the car loosens up and my ScanGauge E begins to show my average journey mpg improving.
Another thing I make great use of is Deceleration Fuel Cut Off, where the engine uses no fuel at all. The ScanGauge E displays that too. Sometimes, depending on the vehicle speed, 5th gear doesn't give DFCO but a change to 4th does. Every little bit helps in achieving good mpg.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on January 19, 2019, 12:59:12 PM
The petrol is made more volatile in winter to evaporate more readily at lower temperatures - summer fuel is more dense than winter fuel which helps get better MPG in summer.  Google 'reid vapour pressure'.

Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on January 19, 2019, 02:07:35 PM
Just looking at these last few posts, this style of driving has real relevance to EV driving. I am sure if/when Jocko gets an EV he will attain significantly better range figures than most. I was out with my walking group this Thursday and my pal came in his 2014 Nissan Leaf. He employs a range of techniques to increase range and low throttle input is definitely one. On cold days, he warms the car up in the drive by sending it a message from his mobile phone. This means the initial warm up is achieved whilst the car is plugged into the mains. He then turns the heating off and puts it back on when he feels the cold. Helps that his car has a winter pack with heated seats and steering wheel.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on January 19, 2019, 02:41:27 PM
The electric car makers do the trick of warming steering wheel and seats rather than actually raising the general cabin temperature and blowing warmed air around as warming cabin up needs too much energy,  what do they do in summer, cool the steering wheel and seats ?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 19, 2019, 02:51:58 PM
I have been a steady driver for years, always trying for good mpg. When I was a company van driver they always remarked on my fuel efficiency. I could get twice the mpg of the worst driver.
It wasn't until after I bought the Jazz I decided to try for real and read up on Hypermiling. I don't go to the extremes that some of those guys do, I would never coast with the engine turned off, or remove the passenger side wiper and mirror, but I did get the ScanGauge E, and though I only use the Instantaneous mpg (something more modern Jazz displays show anyway), it has made me slightly more efficient as a fuel saving driver.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on January 19, 2019, 03:02:37 PM
One thing I'm finding with the CVT is that I'm less certain of how to drive it to gain maximum efficiency than I was with the manual. Overall they are supposed to have the edge over a manual box but I find I am pushing it a bit harder than I would a manual to get decent acceleration - this may have something to do with the Atkinson cycle (about which I know a vanishingly small amount). On the plus side, the very low revs when cruising must save fuel on longer journeys. It's almost like a diesel in this respect - 2000 (ish) rpm at 65 - 70 mph.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 19, 2019, 03:52:57 PM
Can you set the on-board display to show Instantaneous mpg? That is a brilliant tool. Just adjust your right foot to compromise between required acceleration and best numbers.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: John Ratsey on January 19, 2019, 05:59:49 PM
The electric car makers do the trick of warming steering wheel and seats rather than actually raising the general cabin temperature and blowing warmed air around as warming cabin up needs too much energy,  what do they do in summer, cool the steering wheel and seats ?
I would have thought the solution is to use a combined aircon / heat pump which will be variable speed to provide the required output. Typically, 250W of electricity will provide 1kW of heating / cooling although the actual performance depends on the temperature difference between ambient and target. There might also be potential to divert cooling air that's been through the motoras warm air for the cabin.

One thing I'm finding with the CVT is that I'm less certain of how to drive it to gain maximum efficiency than I was with the manual. Overall they are supposed to have the edge over a manual box but I find I am pushing it a bit harder than I would a manual to get decent acceleration - this may have something to do with the Atkinson cycle (about which I know a vanishingly small amount). On the plus side, the very low revs when cruising must save fuel on longer journeys. It's almost like a diesel in this respect - 2000 (ish) rpm at 65 - 70 mph.
Short bursts of acceleration shouldn't have a big impact on the trip mpg. If you need to get the speed up then it might, overall, be better to do the acceleration and then let the engine drop back to the Atkinson cycle mode once up to cruising speed. I recall that when I had a Mk 3 Jazz I found that the car was keen to get to about 3,000 rpm whenever I wanted even modest acceleration - too easy to pull away from some traffic lights and find I was quicly well over 30 mph and above the speed limit. This might suggest that Honda figured out it was better to accelerate + cruise rather than longer slower acceleration + less cruising.

 If you have a standard trip you frequently do then you could compare the trip mpg for different driving styles. However, you need to do such tests under the same weather conditions. We've touched on temperature but wind is another big factor and a moderate wind can cause at least 10% difference in the trip mpg depending on if it's a head or tail wind.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 19, 2019, 06:43:49 PM
Brisk acceleration is the best bet for fuel efficiency. Not wide open throttle but about 80%.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: smilertoo on January 19, 2019, 09:09:51 PM
wait, you're saying faster acceleration is better than taking your time?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 19, 2019, 09:42:15 PM
That is the Hypermilers way of doing it. With 80% throttle the engine works more efficiently. You want to accelerate with the  engine operating around the maximum torque changing gear to keep it there. But only accelerate to the speed you want to reach. If you have to brake you are only wasting energy you used to get to that speed.
Best way to save fuel is anticipation.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: John Ratsey on January 20, 2019, 09:03:05 AM
That is the Hypermilers way of doing it. With 80% throttle the engine works more efficiently.
However, I wonder if this applies to Honda's newer 16 valve engines where half the inlet valves stay closed below around 3,000 rpm in order to improve the fuel mixing and hence the efficiency in this lower rpm lower power range. Honda's recent vehicles with CVT transmission achieve better test mpg than the manual gearbox versions. Those CVT vehicles don't rev to anywhere near the maximum torque range without putting the whip to them as if they think it's less efficient. However, it may just be that Honda feel that customers don't normally want the extra noise which comes with the higher revs.

Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 20, 2019, 11:10:47 AM
The only way to find out is to try both approaches for a few tankfuls and see what returns the better mpg. If neither one wins out then it doesn't really matter.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on January 20, 2019, 11:18:42 AM
That is the Hypermilers way of doing it. With 80% throttle the engine works more efficiently.
However, I wonder if this applies to Honda's newer 16 valve engines where half the inlet valves stay closed below around 3,000 rpm in order to improve the fuel mixing and hence the efficiency in this lower rpm lower power range. Honda's recent vehicles with CVT transmission achieve better test mpg than the manual gearbox versions. Those CVT vehicles don't rev to anywhere near the maximum torque range without putting the whip to them as if they think it's less efficient. However, it may just be that Honda feel that customers don't normally want the extra noise which comes with the higher revs.

To achieve atkinson cycle on newer engines below 3000 they keep all inlet valves open until well into compression stroke and allow mixture ( or just compressed air with direct injection engines like mk3) to escape back into inlet manifold, this lowers compression ratio and makes engine more efficient but also lowers power. This was first introduced in civic 8th gen 1.8 VTEC ( 2006 to 2012 ) but mk2 jazz ( 2008 to 2015 ) did not get it. This reduces pumping losses which are big source of inefficiency on petrol engines, Honda also manage to keep throttle butterfly almost fully open during Atkinson cycle which further reduces pumping losses. Maybe the hypermilers are trying to keep throttle more open to reduce pumping losses during acceleration as pumping losses are due to engine having to suck against throttle butterfly and are highest at low revs when butterfly is normally almost closed on a normal petrol engine.  Direct injection petrol engines behave more like a diesel ( which don't get pumping loss as they don't have a butterfly, power is controlled by timing and amount of fuel injected ).

Original VTEC  12/16 valve engines used to only partially open one inlet valve and fully open the other to induce 'swirl' in the in-going mixture.  This may still be the case on mk2, but not mk1 which only has one inlet valve anyway and no VTEC cams .  The I-vtec mk2  engine has additional trick to move the camshaft timing in relation to crankshaft by means of a helix between the pulley and camshaft.

Looking at this comparison between I-dsi and 1.5 vtec it seems Honda stayed with  12/16 valve method for 1.5 vtec ( article is from Asia ) so maybe still used it for the European 1.2 and 1.4 of the same period.

http://asia.vtec.net/Series/FitJazz/lseries/

Also

https://en.m.wikipedia.org/wiki/Honda_L_engine
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 20, 2019, 11:48:18 AM
As I have said elsewhere, reducing pumping losses are one of the goals of open throttle acceleration. The reason 80% throttle is recommended instead of 100% is that normally 80% keeps the ECU in closed loop mode where 100% takes it into open loop territory, which disregards the O2 sensor. It is a bit like the extra spurt of fuel that full throttle on a carburettor engine gives, derived from the accelerator pump.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on January 20, 2019, 05:14:19 PM
Honda's recent vehicles with CVT transmission achieve better test mpg than the manual gearbox versions.

But the Jazz that went from Lands end to john O'Groats on one tank of fuel was a manual gearbox,  just goes to show that in proper hands the manual box can outperform the CVT in the MPG area.

Maybe by using an economy electronic map for CVT the revs can be kept low as possible even though the accelerator is being pressed hard,  but in sport mode the car behaves more like a spirited driver with a manual box so MPG suffers.  So with a human in charge using experience and anticipation ( and all the other stuff humans can do that computers cannot ) the manual box still outperforms the CVT.

I bet the hypermilers prefer a manual box as well,  as it absorbs least power than other options.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on January 20, 2019, 05:23:50 PM
Honda's recent vehicles with CVT transmission achieve better test mpg than the manual gearbox versions.

But the Jazz that went from Lands end to john O'Groats on one tank of fuel was a manual gearbox,  just goes to show that in proper hands the manual box can outperform the CVT in the MPG area.

Maybe by using an economy electronic map for CVT the revs can be kept low as possible even though the accelerator is being pressed hard,  but in sport mode the car behaves more like a spirited driver with a manual box so MPG suffers.  So with a human in charge using experience and anticipation ( and all the other stuff humans can do that computers cannot ) the manual box still outperforms the CVT.

I bet the hypermilers prefer a manual box as well,  as it absorbs least power than other options.

Without even beginning to understand the science - this actually makes sense. The CVT probably does edge it with a "normal" person behind the wheel but the manual affords more scope for the experienced hypermiler.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 20, 2019, 05:33:57 PM
I bet the hypermilers prefer a manual box as well,  as it absorbs least power than other options.
A true hypermiler would always choose a manual, not just from the power absorption but the fact that they are in control of everything it does. Mind you, some of the things they do are so extreme for fractions of a mpg. Things like moulding body parts, taping off panel joints and door openings and flushing wheels, wheel apertures, and even complete under-bodies!
(http://i53.photobucket.com/albums/g57/ravirai/honda%20fit%20aero%20mods/Crazyhondafitidea2.jpg)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on January 20, 2019, 05:59:26 PM
Wow!

Yes - I've seen some pretty bonkers stuff on hypermiling forums. That car above, especially the back end, looks like my Dad's old Standard Vanguard. A Jazz/Vanguard hybrid.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: John Ratsey on January 20, 2019, 06:37:31 PM
But the Jazz that went from Lands end to john O'Groats on one tank of fuel was a manual gearbox,  just goes to show that in proper hands the manual box can outperform the CVT in the MPG area.
With someone from the Honda factory on board who would have had access to the detailed performance data and thus knew the optimum engine / gearbox settings to get the best economy. They must have worked out beforehand that they stood a reasonable chance of succeeding. If we had access to thie same information then we wouldn't need to be discussing the optimum driving style for getting best mpg.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on January 20, 2019, 07:01:12 PM
But the Jazz that went from Lands end to john O'Groats on one tank of fuel was a manual gearbox,  just goes to show that in proper hands the manual box can outperform the CVT in the MPG area.
With someone from the Honda factory on board who would have had access to the detailed performance data and thus knew the optimum engine / gearbox settings to get the best economy. They must have worked out beforehand that they stood a reasonable chance of succeeding. If we had access to thie same information then we wouldn't need to be discussing the optimum driving style for getting best mpg.

The team stayed below 40mph, maybe some of the people I follow are hypermilers, trouble is they do 40 in 60, 50, 40, 30 and often 20 limits, so maybe 40 is the optimum speed....
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 20, 2019, 09:13:30 PM
I watched the video. Seemingly the car was bog standard with no special help from Honda. The dealer supplied the car and the AA drove the escort vehicle. Following behind the van would certainly help.
For those that ask how far you get after the display shows zero miles left, their car showed zero with 60 miles still to go!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Bigal on January 22, 2019, 09:04:12 PM
Just bought a jazz 1.4 good condition only seem to be getting 38 mpg and that's not going fast any tips why so love guys I'm new to this forum any help muchly appreciated
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 23, 2019, 08:33:08 AM
Check your tyre pressures. I set mine to 35 psig. After a longish run check the wheel centres for heating. That way you can discount a dragging brake.
The rest comes down to driver tweeks. Do you accelerate up behind traffic then have to brake? Anticipation is what gives good mpg. Avoiding the need to brake by leaving a good gap and anticipating the traffic ahead. Use higher gears. I invariably drive round town in 5th, changing down to 3rd for roundabouts. I usually skip 4th, both changing up and down (though I will go into 4th on an uphill section or in flat 20 mph zones).
I never turn the heat on until blue light has gone out. No point in trying to heat the cabin at the expense of warming the engine up. On descents get your foot right off the accelerator. This allows DFCO to operate and engine burns no fuel at all. Foot lightly on throttle negates this.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 23, 2019, 05:03:11 PM
Further to the above post, today I had a trip into Edinburgh city centre, during the morning rush hour, and in hard frost and even freezing fog at one stage. I then travelled across the city centre and out to Danderhall on the southern edge, From there I had a trip out to Dalkeith then back to Danderhall. I then had a run back, along the city bypass, then M8, M9 and M90, before returning to Kirkcaldy. Still in sub zero conditions.
Every start was with a cold engine (blue light on).
My ScanGauge E recorded an average of 49.1 mpg (not far from the actual mpg, going by experience). The average speed was 26 mph with a max of 59 mph. Maximum revs were 2917 rpm.
I use the ScanGauge because my Jazz only has a single mpg meter. The ScanGauge gives me instantaneous readings. If your Jazz can display instantaneous readings then view that while driving.
(https://i.imgur.com/qV2N6DN.jpg?1)
The top display is the instantaneous reading, and the lower the average for the current journey. The secret is to try and keep the top number higher than the bottom one. Things like lifting off just before you crest a hill. Or changing up just before the crest.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: smilertoo on January 23, 2019, 11:55:21 PM
35psi? I have all my tyres at the specified 32psi...i might try a bit higher.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 24, 2019, 06:53:07 AM
I increase the pressures slightly for two reasons. Any slight reduction in pressure between checks means that the always remain above 32 psig. Cold tyre pressures are chosen on the understanding that when the tyres heat up the pressures will rise. My tyres seldom get a chance to warm up as the bulk of my trips are only about 4 miles. The engine barely warms up, never mind the tyres.
The manufacturers choose tyre pressures as a compromise between handling, fuel efficiency and comfort. I sacrifice a little comfort (and it is very little) for a little fuel efficiency.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on January 24, 2019, 10:14:10 AM
That's interesting Jocko. My motoring is even more local and short distance than yours (I follow the 33psi front and 32psi rear as per the manual for the Mk3). I might be tempted to go to 35/34.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 31, 2019, 09:50:35 AM
Filled up this morning, and despite the spell of cold weather we have experienced the second half of January I still managed 52.5 mpg (on-board said 53.2 and ScanGauge 50.5). According to my average speed for the month (27 mpg) that works out at 44% Town.City and 56% Interurban.
What I did notice was that Morrisons, here in Kirkcaldy, are selling 97 RON "Premium". At 121.7p against 114.7p for Regular, I don't think I will be swapping. I'd have to push that figure to 56 mpg to make it worth while, and that is a "summer" number!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on January 31, 2019, 12:27:37 PM
I thought the problem with increasing tyre pressures was essentially it bulges so you get increased wear on the centre of the tread and decreased tyre life. It can also mean decreased grip. I presume you don't get this, Jocko, possibly, as you say, because your tyres often don't warm up fully. I've noticed warm tyres can show 3 or 4 psi higher but the specified pressures are for cold.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 31, 2019, 01:48:32 PM
I thought the problem with increasing tyre pressures was essentially it bulges so you get increased wear on the centre of the tread and decreased tyre life. It can also mean decreased grip.
All the stuff I have read, and there is tons of it on Hypermiling web sites, doesn't point to this. There are many people running their vehicles with the tyres at the maximum recommended pressures as indicated on the tyre sidewall. I would never dream of doing that. To me, that is unsafe, and I have argued using the same reasons you have, but I run 3 psig over the recommended figure (5 for the rears). During the time I have been doing this I have noticed no uneven wear pattern (15,000 miles), and I am certainly not aware of any issues with grip.
The Haynes manual for the car, states that the tyre pressures are for the OEM tyres and "the recommended tyre pressures may vary if any other make or type of tyre is fitted". Add to that the accuracy of the gauge you use to check your tyres and then, who knows what pressure you are actually setting?
I haven't noticed any appreciable improvement in mpg with my elevated pressures. It just stops them dropping below the recommended pressures between checks.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on February 01, 2019, 11:48:04 AM
Thanks Jocko, it's what I thought but wanted to be sure. I did the same with my old tyres which lost about 6psi a week. Just had them all replaced and they cleaned the corrosion off the alloys, now holding pressure and more comfortable even at higher pressures. So I'll keep them on the high side.
Also my pump and pen type pressure gauge don't agree. 
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on February 22, 2019, 07:21:26 AM
Disappointing fuel consumption at the moment. Today's top up was only 50.8 mpg over 396 miles. Considering how mild the weather is I would have expected better.

Actual: 50.8       Dashboard: 53.1    ScanGauge E: 51.0
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on February 22, 2019, 08:57:43 AM
I always suspected the 1.2 of being a good engine. I wish I could get something like from my 1.4. Still nudging the 40 mpg mark. Much of that will be down to short journeys though a 150 mile round trip to the coast only got the dash display up to 47.

Returning to the old hypermiler's trick of accelerating open throttle to reduce pumping losses I think it may be just that, an old trick. I'm now getting real time mpg display from an OBDII reader. The further I push the pedal the worse the mpg. I suppose because the pedal is no longer a throttle control it's a pot (potentiometer) that generates an electrical signal demanding power from the ECU. It's striking how the slightest movement in the pedal makes the figure plummet. But then it also shows coasting gives better mpg than engine braking. So either something in my engine stops the fuel cutting off altogether or the way it calculates mpg is misleading. Time will tell - hopefully.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on February 22, 2019, 10:02:28 AM
I very, very seldom open my throttle fully. Once it goes out of closed loop it guzzles fuel. The Deceleration Fuel Cut Off only works above certain rpm. On a slower descent it is better to select 4th, or sometimes even 3rd, to get DFCO to cut in. Above 40 mph then 5th does the trick.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on February 22, 2019, 07:29:27 PM
That's what I thought. The suggestion from the mpg figure is that for some reason my fuel is never cutting off. I'll see if I can get the OBD reader to tell me directly.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on February 22, 2019, 08:34:41 PM
Disappointing fuel consumption at the moment. Today's top up was only 50.8 mpg over 396 miles. Considering how mild the weather is I would have expected better.

Actual: 50.8       Dashboard: 53.1    ScanGauge E: 51.0

I'd be punching the air and handing out cigars with those figures!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on February 22, 2019, 09:53:33 PM
I'd be punching the air and handing out cigars with those figures!
There was a time I would have been too. I remember being jubilant when my first ever tankful returned 48.3, which after 24 - 28 mpg from my Volvo was brilliant. But I have  got used to better. Today's top up knocked my overall lifetime figure (over 23.5K miles and displayed below my Avatar) from 54.2 down to 54.1. Entirely the wrong direction.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on February 23, 2019, 05:07:13 PM
The suggestion from the mpg figure is that for some reason my fuel is never cutting off. I'll see if I can get the OBD reader to tell me directly.
To get DFCO to work, make sure you are removing your foot entirely from the throttle. If not you may be sending enough of a signal to have the ECU giving the injectors an input, and passing fuel.
Another thing to try, using the OBD, is to monitor the fuel use on a stretch of road then very slightly reduce the pressure on the throttle. You can usually add a couple of mpg to the display without affecting the speed. Sometimes more than a couple of mpg.
Another thing to do is to lift of the throttle before cresting a hill, not as, or after you crest it. Let the momentum of the car do the work.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on February 24, 2019, 09:04:06 AM
Yes my foot is entirely off the pedal. I might have a go lubricating the linkages in case it's not fully releasing. Though tickover is around 600 rpm which suggests that's not the problem.

And yes I had noticed how backing off on the pedal improves the fuel consumption. I'm currently learning all the tricks to improve mpg. I may see a benefit when I top up. Unfortunately I seem to be making a lot of short trips which undoes my good work  :(
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on February 24, 2019, 11:57:39 AM
I was thinking about my "poor" numbers and I realised that I am doing silly short journeys that a year ago I would have left car and walked. My joints are giving me gyp just now. This morning I drove the 600 yards to Lidl's, for croissants, then drove home again (car out of garage and then back in again). No wonder my mpg is suffering.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: TheFlyingPostman on March 03, 2019, 03:23:57 PM
Other day I though it will be a fun to test of fuel economy rather than the speeding. I start from my local petrol station fill it up top 41 litres (43 litre tankful) and drove it steady in 'D' mode for 153 miles to Bristol on the M4 at 60mph the rev is variety from 1,700 to 2,400rpm it depend for going up and down the hill. When I have arrived at Bristol pumps calculator is 53.6 mpg. My trip computer said 55 mpg.

After finished to exploring Bristol without used the car, I went back to home on the same motorway lucky there was no traffic at Heathrow M25 at night while used the 7 speed mode at 60mph about 2,500rpm-ish.

The result on 7 speed mode was impressive than in the D mode of 57.5 mpg! Otherwise I thought the 'D' Mode was in a better fuel consumption. Next time I will used the 7 speed mode is fun on the motorways. I am not sure but I think the 7 speed mode would be in a terrible mpg on the countryside road than the 'D' mode.

 
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on March 11, 2019, 07:08:32 AM
Another disappointing fuel figure. 51.2 mpg. The onboard display was wildly off this time showing 57 mpg. It is never usually as far out as that.

Actual: 51.2       Dashboard: 57.0    ScanGauge E: 53.0

On Saturday, after a good long run, my wife suggested we stop for an ice cream before reaching home. We went to Divito’s ice cream parlour in Crossgates (the best ice cream for miles). After a brief stop for our cones we continued on home. Now turning the ignition off for about 3 minutes resets the current journey and displayed average mpg as shown on the ScanGauge E, so from Crossgates to home it calculates the mpg for that trip. For the 11 miles home, via Cowdenbeath and Auchtertool, the ScanGauge showed an average of 74 mpg. There is a 400 foot drop along the length of the journey with a fair portion through 30 mph limit. It just shows how good the mpg can be in town when you can drive for a fair distance at 30 mph without lights, junctions or traffic hold ups. There is a section of 20 mph but luckily it is, if anything, predominantly downhill. There is also a fair section with short sharp uphill sections, then long gradual downhill stretches where you can get off the gas and enjoy the benefits of Deceleration Fuel Cut Off.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on March 12, 2019, 09:14:10 AM
After just about 6 months and 3000 miles my 'grand' average from my first top up to yesterdays is (drum roll?) 41.6 mpg

My best tankful was 49.8 and worst 34.4!

A bit disappointing but it's all those short journeys.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on March 12, 2019, 10:17:31 AM
It is not so much the short journeys more the nature of the journeys. My daily driving starts with 4.1 miles at 06:15 (in town but almost no traffic) and ScanGauge usually shows about 50 mpg. I then do the same journey at 11:00, with fairly busy roads, and ScanGauge can show as little at 44 mpg. Occasionally, in between these two trips I will pop to the shops (which can be anything of a round trip of 0.6 miles to 2 miles), again in traffic. I do that Monday to Friday, week in and week out. On a Saturday I do another round trip of usually 77 miles (on mainly country roads and dual carriageway). I seldom drive in heavy traffic. Traffic lights are few. All of my driving is on roads I drive regularly and know how to get the best out of the car. So as I said, not so much the length of the journeys.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on March 12, 2019, 12:15:51 PM
Fair point. My trips often start with one mile crawling through Saltaire's awful traffic or that mile long hill I mentioned. Hills every where as a matter of fact  :)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on March 12, 2019, 01:17:52 PM
Fair point. My trips often start with one mile crawling through Saltaire's awful traffic or that mile long hill I mentioned. Hills every where as a matter of fact  :)

Much the same in Shropshire,  and you seem to use more fuel going up than you save going back down, I know there are benefits to leaving car in gear and letting throttle close entirely but if there is not much traffic and there is a downhill followed by a long flat or an uphill I will coast down and find i can get much farther along the flat or up the next hill  without  touching the throttle by coasting without the car engine absorbing the free gravity energy that the car is able to build up.  Obviously its a judgment call because if there is other traffic around or you have to stop for a junction at the bottom of the hill it is better to use engine braking.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on March 12, 2019, 02:44:50 PM
Yes, interesting (to me). I've noticed with my instantaneous mpg display that although a steady speed give a figure in the 50s or 60s the slightest acceleration and it drops to below 30. Get nippy and it's in the teens. Climbing a hill is exactly the same as accelerating and petrol engines don't like it. I think that accounts for why you don't get back going downhill the extra you put in going up.
Plus, of course, you lose energy to air and rolling resistance all ways round. It's the clause in Sod's law known as the second law of thermodynamics.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on March 12, 2019, 02:50:33 PM
That is the benefit I have with driving the same route, over and over. I know where it is beneficial to coast, when to select a slightly lower gear or when just to lift off in 5th. It is definitely a judgement call. On my daily journeys I even coast up hills to junctions and the like, knowing exactly when to start coasting so I arrive at the junction at the correct speed. I think of it as long gear changes. I slip it out of 5th before the junction, and select 3rd as I reach the junction. Not so much freewheeling as a l-o-n-gs-l-o-w gear change.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on March 16, 2019, 07:03:59 PM
Today started with torrential rain, mixed with sleet and snow, as I popped to the supermarket. When I set off on my usual 80 mile Saturday trip it was snowing and starting to lie. After about 12 miles it turned to sleet then rain, with flooding and standing water. The return journey was in near monsoon rain. (At one spot, on the M90, while doing 60 mph in lane 1 a car in lane 2 struck deep flood water. For several seconds I could see nothing through the windscreen. Frightening.)
According to the ScanGauge E my mpg for the day was 46 mpg. Well down from the usual 56 mpg, as experienced at this time of the year!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on March 17, 2019, 10:45:49 AM
Today I brought the car out of the garage, switched off to lock garage door, drove to local supermarket, shopped, drove home , stopped car, opened garage door and reversed in. 0.7 miles in total. ScanGauge E mpg for day, 25.9. It is no wonder my overall mpg figures are dropping.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: John Ratsey on March 17, 2019, 11:26:06 AM
No time for the engine to warm up!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on March 25, 2019, 07:20:09 AM
I have had the feeling that the car has been a bit "stiff" this past couple of weeks. I has not been coasting all that well and the ScanGauge has shown poor figures. I even checked the wheel centres, yesterday, for heating and signs of brake binding (all okay). This morning I went in for petrol, which has gone up in price, and I expected to pay around £45. When it cut off at under £40 I was surprised. On working out my figures I have achieved 57 mpg (dashboard display said 55.5 mpg) and I had to make an offset to ScanGauge.
I would have expected a figure like that, as I have had 80 mile outings on Friday, Saturday and Sunday but was still surprised to see it.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on March 25, 2019, 10:07:51 AM
I know mine's a Mk3 but this is the most interesting thread for mpg matters!

One thing I'm trying to get to grips with is driving the CVT in the most economical way. Official figures (for what they are worth lol) indicate that the CVT is, overall, more efficient than the manual but I'm finding that the improvement over the Mk 2 manual is marginal and I think most of that improvement is down to changes in the engine on the MK3. I think I am driving in a less economical manner with the CVT. Part of that might be attempting to by pass the initial sluggishness by flooring the gas pedal and finding the revs going up to nearly 4,000 rpm on occasions and this is in a 40 mph speed limit!

Ideally, I need to be getting back to the no higher than 2,500 rpm idea before changing up (or the CVT selecting a higher ratio).
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: John Ratsey on March 25, 2019, 11:09:21 AM
I know mine's a Mk3 but this is the most interesting thread for mpg matters!

Ideally, I need to be getting back to the no higher than 2,500 rpm idea before changing up (or the CVT selecting a higher ratio).
I agree about this interesting discussion.

The challenge with the Mk 3 Jazz, particularly the CVT version, is keeping it in the more efficient Atkinson cycle mode. I found that there was a gap in the performance characteristics and it was difficult to achieve smooth acceleration (I recall that the sales info at the time claimed this to give a more sporty feel): Either be very easy on the right foot and accelerate slowly or push a bit harder and be quickly breaking the urban speed limits. Hence after a year my Mk 3 was traded in for a CVT HR-V. The latter doesn't have the Atkinson cycle mode and has a better relationship between pushing pedal and performance. So far, the HR-V has averaged 50.4 mpg compared to 57.8 mpg I achieved during a year with the Mk 3 Jazz - only 13% difference for similar driving style and conditions.

I thought I had read somewhere that the Mk 3 Jazz refresh has some tweaked settings for the CVT behaviour which might be to address this performance gap, but can't now find anything.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on March 25, 2019, 11:25:30 AM
Part of that might be attempting to by pass the initial sluggishness by flooring the gas pedal and finding the revs going up to nearly 4,000 rpm on occasions
Try switching your dashboard display to instantaneous mpg. That is my guide. Opening the throttle wide is not a bad ploy, but flooring it is not a good idea. About 80% is a reasonable amount. You want to keep the ECU in closed loop control. Too much throttle gets you into open loop, and that is a bit like the old accelerator pump on a downdraught carb.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on March 25, 2019, 08:00:01 PM
Checked my tyre pressures and they are spot on. Since seeing how good my mpg figure was I found my coasting a lot "freer", a bit like how the car always feels smoother on the way back with a fresh MOT than it does on the way to the testing station.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on March 26, 2019, 11:42:23 AM
Today I came home from Edinburgh and came along my usual route from the A909, via the B925 to the A910. 6.0 miles, junction to junction. I reset my Current trip as I started, but had a disappointing journey spoilt by a lorry reversing into a property and a man with a STOP/GO board for white lining. My ScanGauge E still recorded 92.1 mpg for the 6 mile trip. Pleased with that.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Kiwikea on April 01, 2019, 02:32:29 PM
Hi I have a 2007 jazz sport 1.5 cvt7, I get 46-50 mpg  for the hills I drive over in New Zealand
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on April 01, 2019, 04:46:15 PM
Welcome. We didn't get a 1.5 Jazz until the 2019 model Sport. 46 - 50 is good mpg for the larger engine.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: TheFlyingPostman on April 03, 2019, 04:14:45 PM
I have K&N performance filter, NGK IRIDIUM spark plugs and EGR blank I have see massive improve in performance with lightness on right pedal 3 mpg more than pervious 53mpg. Very pleased with it.

Got this from https://www.ebay.co.uk/itm/8x-NGK-IRIDIUM-IX-UPGRADE-Spark-Plugs-HONDA-JAZZ-1-4-i-DSI-TWIN-SPARK-02-3764/360475871112
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on April 20, 2019, 05:34:46 PM
Nice warm day today (too warm as I have no air con!). Easter traffic was really busy. The combination of these factors meant I managed 58.9 mpg (ScanGauge E) for my usual 80 mile, Saturday, round trip.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on April 22, 2019, 07:11:48 AM
Filled up with petrol today. It was just a top up, as I had a Morrisons 5p/litre off voucher, and the promotion ends today. Calculated figure was 57.1 mpg which, surprisingly, was the dash read out as well!
Petrol was cheaper to buy, when I got the voucher, than it was this morning with the 5p off !!!!
And it is to get dearer. The US has just announced hardening sanctions against Iranian oil, which has already pushed up Brent crude.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: smilertoo on April 22, 2019, 10:37:15 AM
long motorway run yesterday pushed my mpg from 38 to 45.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on April 22, 2019, 12:22:31 PM
long motorway run yesterday pushed my mpg from 38 to 45.
I find my best mpg figures on the motorway are around 60 mph on the speedo, 53 mpg on the GPS.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on April 29, 2019, 06:56:46 AM
Got a respectable figure for my mpg this tankful. 57.7 mpg calculated (Fuelly.com). This week I have done a lot of longer runs (80 miles), albeit many into Edinburgh city centre, and almost no daily commutes. The warmer weather makes a difference too.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on April 30, 2019, 09:07:04 AM
That's more than respectable, Jocko, it brilliant. I'm still not getting anywhere near. I'm definitely becoming very curious what I can do to improve mpg. I do all I can with driving style. I've now done a full service with standard parts but that's only got me a couple of mpg (I have no fixed driving pattern so it's not easy to compare).

I tried an EGR plate but it didn't make much difference to running or economy. So I suspect, Flying Postman, it may be down to the iridium plugs. They don't just last longer, they give a better spark. The physics is that smaller electrodes give higher electrostatic shear forces that ionises the air more effectively. It's the same reason lighting conductors are sharp. The air filter probably helps. Do you have the cone one or the one that replaces the standard filter?

The latest in my search for the lost mpg is to try a catalytic converter cleaner. They say carbon deposits build up and my cat seems to be the original 10 year old one. I'm thinking that might mislead the oxygen sensors and cause the ECU to bung too much fuel in. I'll post when I've used a tankful and topped up. According to the dashboard display I'm doing 46 mpg which is 3 or 4 up on usual, though I have also had some longer runs.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on April 30, 2019, 10:17:08 AM
I use standard plugs (not Iridium) and the eight plugs have been in for two years. I intend leaving them another year before I change them. Air filter is just bog standard from a local motor factor. It has been in two years and about 18K miles, so I may change it next service. Oil is just cheap 5w-30 synthetic.
Cat was replaced two years ago but I actually noticed a 10% drop in mpg immediately after replacing it.
I do set my cold tyre pressures to 35 psig and regularly feel my wheel centres after a trip (in case of any brake rubbing).
I tend to drive for economy, with little brisk acceleration, unless road conditions demand it. On a downhill stretch, if there is nothing behind me, I will let the car pick up speed by its self, rather than by accelerating (I am retired, and when I am in the car by myself I am seldom in a hurry). I seldom drive fast. I find that on the open road a GPS speed of around 53 mph (just under 60 on speedo) suits me and returns best numbers.
I do have my ScanGauge E fitted to binnacle and it displays my trip average and instantaneous mpg, and I constantly try to keep the latter higher than the former.

(https://i.imgur.com/qV2N6DN.jpg?1)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on April 30, 2019, 10:38:26 AM
The cruising speed on the motorway is a biggie. There are stats available but the difference between 60 mph and 70 mph is significant. Found this out in 2017 on a trip down to Cornwall. A longish cruise, mostly at 70 or even a bit above, returned 49 actual in my 1.4 Mk 2.

My best return in that car was a tad over 56 mpg. This was achieved on the M56/M53 at a busy time when it was actually almost impossible to reach 70.

I used to aim for 75 on the speedo (reckoning that would be an actual 70). I now aim for dead on 70 (setting cruise to that if possible) and this shows as a "real" 66 mph on the sat nav. Quite a decent speed and a good compromise between speed and economy
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on May 07, 2019, 01:11:49 PM
Topped up today and the last 350 very mixed miles averaged 54.8 mpg. Very pleased with that  :D. Hopefully it was the cat cleaner what did it. I did have to replace the back box too. Could the old one have been obstructing the flow?  Of course it could be a duff pump which cut out too soon I suppose.
All this on whatever supermarket petrol is cheapest. Usually Asda, today Sainsburys.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on May 07, 2019, 01:26:10 PM
I also use supermarket fuel. Never found and advantage not to.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on May 08, 2019, 10:18:43 AM
I should have said the reason I'm not sure about the figure of 54 odd mpg is that the dash only showed 45.1. Has anyone ever had the dash display be pessimistic?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on May 08, 2019, 10:32:46 AM
Has anyone ever had the dash display be pessimistic?
Since I started recording the display against the actual (coming up for a year) I have had two pessimistic readings. In both instances they were for actual values better than 60 mpg. Perhaps the error is on a sliding scale, with more optimistic readings at lower actual values and more accurate and ultimately pessimistic read outs for higher actual values (I have had the display and actual value match once, at 57.1 mpg).
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on May 08, 2019, 01:40:12 PM
Thanks. I'll know for sure when I next top up. Which might be a while  ;)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on May 08, 2019, 09:54:35 PM
I also use supermarket fuel. Never found and advantage not to.

I'm on my second tank of Irish petrol (Apple Green) - sold from their own forecourts and catering outlets. Supermarket prices and no performance issues at all.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on May 17, 2019, 10:24:17 AM
Yesterday, on my way into Edinburgh city centre, I spent 10 miles on busy single carriageway roads stuck behind an articulated aggregate truck. It kept a constant 35 - 40 mph as, with no chance to overtake, did I. My ScanGauge showed me averaging better than 60 mpg! Unfortunately, an hour in crawling evening rush hour traffic, on my return, robbed me of any benefit from my outward journey.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on May 17, 2019, 11:14:33 AM
The 54+ mpg figure was down to the pump cutting off early.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on May 17, 2019, 11:57:09 AM
That is why the average over a spell is better. I log my fuel usage here: www.spritmonitor.de/ (http://www.spritmonitor.de/) (there is an English option) and the number below my avatar is my running average over my life with the car (approaching 3 years).
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on May 17, 2019, 03:24:00 PM
Thanks. I've been using fuelly which shows an average of 42.1 since last October. Which is quite good amongst the figures there.  - though they do vary a great deal.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Eddie Honda on May 17, 2019, 04:27:19 PM
Haven't been on for ages, but FWIW the 2005 Jazz is doing okay on the fuel at around 123k now. (bought at 68k)

Average on the left is 43.0 mpg which is mostly wifey's doing. I rarely drive the thing and whilst I record everything going in and out the mpg is reflective of average conditions/driving/use (including the odd roofbox/trailer runs) rather than economy driving - I'm more interested in what it costs per mile/km to run and how long various parts last.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on May 17, 2019, 05:45:13 PM
Thanks. I've been using fuelly which shows an average of 42.1 since last October.
I use Fuelly as well. Gives lots of good statistics.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on May 24, 2019, 07:40:05 AM
Topped up with fuel this morning and collected my ScanGauge data for the tank, as I normally do. One of the parameters it stores is the hours driven, and it is quite scary to see that every tankful of petrol used involves me driving for 13 - 14 hours. As I usually fill up once a fortnight this equates to around a solid fortnight of my life, every year, driving my car. Just as well I love driving.
Owing to medical issues, today is my wife's last day at work for the next month or so. It will be interesting to see how my numbers change without my daily drop off and pick up. Mind you, I tend to get good figures for these trips (especially the early morning one), so I might even see a deterioration in mpg over the near future.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on June 03, 2019, 09:53:36 AM
Yesterday, I had a medical emergency which required a dash over to the south of Edinburgh. Despite 80+ mph (50 mph average), loads of acceleration and brakes instead of lifting off, the ScanGauge still showed 50 mpg for the trip.
Today I filled up the near empty tank (not quite my usual top up but in preparation for hospital visits) and the calculated mpg was 57.5 for 383 miles.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on June 04, 2019, 07:40:06 AM
Yesterday afternoon I had a trip back from hospital, in Edinburgh, just as the evening rush hour started. I had crawling traffic right to the outskirts of the city, then a three mile queue onto the Queensferry Crossing. My Scan Gauge showed my average mpg as less than 45. And that included the faster bits elsewhere on the journey. I feel sorry for drivers who experience that on a daily basis. An ideal daily journey for an electric vehicle.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on June 04, 2019, 08:16:54 AM
"An ideal daily journey for an electric vehicle." And it's probably the driving most people do most of the time. However I think we sink so much money into our cars for that dream of the open road much loved by advertisers. I know I do  ::)

As for Fuelly there are a lot of statistics, not certain how good they are. I was browsing all the data on Mk1 Jazzes and saw one tankful of zero mpg and another over 94. The devil is in the detail. Though to be fair the graphs exclude such outliers.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on June 04, 2019, 09:25:43 AM
There are some real numpties filling in data that skews the results. However, if you look at Jazz by year you get good data when you disregard the obviously spurious entries. Most statistical data disregards top and bottom groups using standard deviations.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on June 04, 2019, 09:56:49 AM
"An ideal daily journey for an electric vehicle." And it's probably the driving most people do most of the time. However I think we sink so much money into our cars for that dream of the open road much loved by advertisers. I know I do  ::)

As for Fuelly there are a lot of statistics, not certain how good they are. I was browsing all the data on Mk1 Jazzes and saw one tankful of zero mpg and another over 94. The devil is in the detail. Though to be fair the graphs exclude such outliers.

I use Fuelly and I like a good pie chart and a graph. There is no doubt, however, that some members of the site are a bit lacking up top so you see Honda Jazzes with mpg figures of 25 to the gallon or, in one case, over 90 if I recall. I think people will often put partial fuel ups in and categorise them as full ones.

Garbage in garbage out as they say.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on June 04, 2019, 11:41:02 AM
Very true. Though not everyone has an eye for detail.

For instance. I use a bluetooth OBDII dongle with Torque Lite on my phone. First, it's even more optimistic than the dashboard display. So only useful for indicating changes in consumption. One curious thing I've noticed is when say, going downhill off the throttle, the tiniest amount of pressure on the accelerator gives a better mpg figure than no throttle at all. Coasting in neutral shows better still (just out of curiosity, you understand). Typically 160, 110 & 80 US mpg. What I can't tell is whether this is real or just a quirk of how it calculates mpg. Possibly the latter, as it doesn't have much effect on the dash displayed figure. I do wonder if my throttle body or  some part of the emissions control stuff needs a clean. Of course if I do get round to tinkering with that I'll report results.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on June 04, 2019, 12:50:40 PM
I use the ScanGauge E, which connects to the OBD II port as well, but it is stand alone. It displays the instantaneous mpg(UK) and on a light throttle it will regularly display 90, 120, 170 mpg, and that is a real figure. If you think about it, to average 55 mpg for every minute you are doing 20 mpg you must also be spending a minute doing 90 mpg. And in a normal day's driving you will spend a lot of time doing less than 20 mpg (accelerating away in 1st for instance).
With the Jazz, when you lift off the throttle completely (provided the road speed keeps the engine revs up enough, 1800 - 2000 rpm), then the Jazz uses NO FUEL WHATSOEVER, in common with most other modern cars. This is called Deceleration Fuel Cut Off or DFCO. The ScanGauge indicated 9999 mpg. Coasting in neutral, with engine running and foot off the throttle requires petrol to keep the engine running, and I regularly see 200 - 400 mpg in this mode (depending on vehicle speed).
If your car runs smooth, and you have no management light, I would leave well along. The issue is with the software you are using.

(https://images-na.ssl-images-amazon.com/images/I/714RV74BTmL._SL1500_.jpg)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on June 04, 2019, 01:38:28 PM
That's just it, is my fuel cutting off but not being reported? I don't see why my OBD wouldn't get the message. More likely, with 112k miles, something needs a clean.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on June 04, 2019, 01:57:06 PM
Some software doesn't register DFCO. The software you are using doesn't even register mpg (UK). To have a failure that you are talking about would result in an engine management light. You wouldn't be seeing 54.8 mpg over 352 miles. My Jazz has done 114,000 miles and nothing needs cleaned.

(https://i.imgur.com/qV2N6DN.jpg?1)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on June 05, 2019, 08:06:37 AM
Hmm. That 54.8 wasn't right, though I fill to the first cut off the tank before must have been very full and the one after not so much. My 42.3 average is OK I'm just looking round for what I might do to improve it.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on June 09, 2019, 12:38:46 PM
Had a fill up this morning, after 336 miles. I like to let tank get lower than that but I have an early morning hospital run tomorrow and didn't want the hassle of an early morning trip to the filling station.
I was surprised to see a calculated value of 53.8 mpg as I have had several high speed runs with rush hour crawls in between (as well as an "Italian Tune Up"). I have had no chance to drive for economy for a couple of weeks now. It looks like that figure could be easily achievable in a 1.2i-DSi, at this time of the year.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on June 24, 2019, 07:11:58 PM
Another short fill today. 334 miles and 25 litres. Gave me a very pleasing 61.4 mpg, which is all the more remarkable seeing this has been achieved in and out of Edinburgh, on a more or less daily basis.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on June 25, 2019, 09:14:27 AM
Honest envy here  :o
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on June 27, 2019, 06:27:07 PM
Yesterday, my wife had life saving surgery, and today I had a trip to Royal Infirmary of Edinburgh to visit her. However, I first had to visit her mother in The Western General Hospital. So I drove from Kirkcaldy into Edinburgh city to the Western, then a crawl, the 12 miles to the Royal, via Newhaven, Leith, and Seafield.
After a happy visit with my lovely wife I had another crawl to the City Bypass, then a smooth journey home to Kirkcaldy.
My ScanGauge E (which has currently been pessimistic compared to my calculated mpg figures) gave me 60.8 mpg for the 75 mile trip. The average speed was calculated as 28 mph! The Fibometer is currently displaying 64.9 mpg for this tank, so far.
I think the fact that most of my miles are single crewed at the moment, as well as the warm weather we are enjoying, have made a big difference.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on June 28, 2019, 08:46:07 AM
Oddly the warm weather doesn't seem to have improved my mpg at all. Stuck around 42 mpg. Maybe it's time to try a tank of the good stuff.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: d2d4j on June 28, 2019, 09:41:01 AM
Hi

This is my once and only highest figure I have managed.

Apologies for photo, taken whilst driving by my wife but the figure is showing 60.9 mpg at constant 62 mph by satnav speed using cruise control on motorway

Usually I attain anywhere between 46 - 54 mpg

I was happy at that figure but don’t think it was my driving. Just a fluke and yes, I know it’s a fibometer

Many thanks

John

(https://uploads.tapatalk-cdn.com/20190628/f01bbb1faf2956b19f639880eb8e53fb.jpg)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on June 28, 2019, 09:58:57 AM
I only ever reset the Fibometer when I fill the tank, but it gives an indication of whether to expect good or bad figures when I do my sums.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on June 28, 2019, 07:02:02 PM
Today I had a run to the Royal Infirmary of Edinburgh, and despite over 5 miles of queuing, stop start, traffic, the ScanGauge indicated 60.7 mpg. There was almost 4 miles of traffic trying to get over the Queensferry Crossing. Why they built a bridge with only a dual carriageway when there are two dual carriageways merging at each end, heading North and South, beats me. Other than overnight, there is always slow traffic trying to head North. Must be the attraction of the Kingdom of Fife!

(https://i2-prod.edinburghlive.co.uk/incoming/article15091245.ece/ALTERNATES/s615/2_Queensferry-Crossing-Opens-To-Traffic.jpg)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 02, 2019, 11:56:57 AM
Filled up again today, once again with 97 octane, and car returned 60.8 mpg. Onboard display was 6% optimistic, with 64.2 mpg
I have now averaged 59.8 mpg over the last 6 fill ups and 2,350 miles.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: mutts nutts racing on August 03, 2019, 12:37:18 AM
Just picked up my first Jazz today. 02 plate. Just finished a 12 hour day delivering pizza and my dash says 58 mpg. Dead chuffed with that. Been a really pleasure to drive today..... except the 'foggy' headlamps. Hope there is some tips one here somewhere. :)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on August 03, 2019, 09:29:32 AM
Just picked up my first Jazz today. 02 plate. Just finished a 12 hour day delivering pizza and my dash says 58 mpg. Dead chuffed with that. Been a really pleasure to drive today..... except the 'foggy' headlamps. Hope there is some tips one here somewhere. :)

Many threads on here about cleaning up cloudy headlights,  ranging from taking an angle grinder to them down to toothpaste ....good luck

https://clubjazz.org/forum/index.php?topic=9706.msg54927#msg54927
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 03, 2019, 03:10:35 PM
I used Windowize, and found it really effective.
58 is a great number for around town. I get my best mpg figures in town, or certainly, in traffic. Be aware that the Fibometer on the dashboard tends to be a bit optimistic.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 03, 2019, 03:46:25 PM
I have the ScanGauge E fitted to my car and it displays an average mpg for the current journey, along with the instantaneous mpg.

(https://i.imgur.com/qV2N6DN.jpg?1)

It is more accurate than the Fibometer as it is calibrated at each top up.

Most of my regular journeys tend to be over the same routes and in pretty much the same sort of traffic. About the only real variable is the weather. As a result I can check my average mpg at known points and it gives me an idea if I am doing better or worse than other journeys.
Today, my wife, who is recovering from surgery, was in the car with me. It has been a while since she has been well enough to accompany me, so most of my trips have been single crewed. What I noticed today, was at all the salient points, my average mpg was not as good as recently. It is what all the mpg forums say. Reduce the weight in the car to get the best mpg. Once she is fully recovered she can start running along behind me.

Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on August 03, 2019, 05:21:30 PM
I used Windowize, and found it really effective.
58 is a great number for around town. I get my best mpg figures in town, or certainly, in traffic. Be aware that the Fibometer on the dashboard tends to be a bit optimistic.

Interesting about getting best figures in town. I posted on the Mk3 forum about my experiment with 97 RON petrol but another thing occurs to me. Typical journey, for me, is 3.5 miles return to the supermarket with the engine getting cold whilst we do the shop. Now here's the thing. I filled up to take advantage of a 10 pence per litre offer at Sainsburys. After that did 3 more journeys to feed my daughter's cat. This journey is 6 miles return with only a 10 minute stop to give Sam his food. On the fibometer I am showing 56 mpg which is almost certainly a genuine 52.

I can see where you are coming from. Applying usual eco driving techniques although not full hypermiling.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on August 04, 2019, 10:03:56 AM
Interested to hear how you get reliable figures from topping up Jocko. I've been logging mine on fuelly but it varies wildly depending when the pump cuts out. Even using the same pump. I'd read you shouldn't fill to the brim in case fuel gets into the charcoal canister for emissions control. But then I think on the Jazz that's under the bonnet and above the level of the filler. Anyone know for sure?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 04, 2019, 11:44:39 AM
Filling to the brim means topping off, right up into the neck. I used to do that back in the old days, when filler pipes only had an overflow and no emission controls. I fill to the first click off with my Jazz. My old Cavalier would click off several times during topping up. With that I kept the nozzle in the tank and filled until I got two click offs in quick succession.
springswood: Try that for future top ups and see if that smooths out your numbers.
Also, be aware that unless you do similar journeys every tankful, then you can get varying mpg figures.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on August 04, 2019, 01:44:07 PM
I wait until the first click. I am pretty sure all pumps are slightly different plus minor differences in how hard you squeeze the trigger will mean earlier or later cut offs. That might mean each individual mpg figure might not be dead right but, over time, you will get an accurate average mpg figure.

I could get this by deleting 4 mpg from the fibometer on trip B (which I don't zero) but I like the graphs and pie charts on Fuelly!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 04, 2019, 02:49:12 PM
My Fibometer never twice shows the same degree of error. I too like Fuelly, with all the stats it generates.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on August 05, 2019, 10:30:49 AM
Thanks guys. My driving is a bit unpredictable (in its mix of long and short journeys) but I've noticed that it takes anywhere from 10 to over 100 miles before the needle moves off full, and this correlates with good or bad figures so I think that's mostly it.

Yes I love all the graphs on fuelly too.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: MartinJG on August 05, 2019, 12:44:54 PM
I have the ScanGauge E fitted to my car and it displays an average mpg for the current journey, along with the instantaneous mpg.

(https://i.imgur.com/qV2N6DN.jpg?1)

It is more accurate than the Fibometer as it is calibrated at each top up.

Most of my regular journeys tend to be over the same routes and in pretty much the same sort of traffic. About the only real variable is the weather. As a result I can check my average mpg at known points and it gives me an idea if I am doing better or worse than other journeys.
Today, my wife, who is recovering from surgery, was in the car with me. It has been a while since she has been well enough to accompany me, so most of my trips have been single crewed. What I noticed today, was at all the salient points, my average mpg was not as good as recently. It is what all the mpg forums say. Reduce the weight in the car to get the best mpg. Once she is fully recovered she can start running along behind me.

Absolutely. No room for slackers.

PS - Hope everything is now OK on the health front though.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 05, 2019, 01:10:08 PM
Thanks Martin. She has chemo and radiotherapy to go, but she should be finished with surgery.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: MartinJG on August 05, 2019, 06:30:45 PM
Thanks Martin. She has chemo and radiotherapy to go, but she should be finished with surgery.

Fingers crossed.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 06, 2019, 02:37:38 PM
So far, on my current tankful, I have done 245 miles. The Fibometer is saying 66.5 mpg. Not that I believe it though.
I only do shorter journeys (no more than 100 miles in a day), and fuel gauge never seems to move. However, when I switch ignition on the next day, it will have dropped a bit. Anyone else noticed this?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Outcasst on August 06, 2019, 05:18:59 PM
I typically get around 45MPG. Mix of Urban and countryside roads.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 06, 2019, 07:04:55 PM
Welcome, Outcast. My mileage, mix wise, is similar. I find country roads great for mpg. Motorway, the worst.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 11, 2019, 09:59:22 AM
My mother-in-law is not keeping well, in fact she was readmitted to hospital yesterday, so I have been doing regular runs over to the south side of Edinburgh. I topped up today, slightly earlier than I would like at 452 miles, and the calculated mpg was 65.5. The Fibometer said 62.9 and my ScanGauge was wildly pessimistic at 58.2. I must have input a wrong calibration value when I did my previous top up to put it as far out as that!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: sparky Paul on August 11, 2019, 10:36:55 AM
My mother-in-law is not keeping well, in fact she was readmitted to hospital yesterday

Sorry to hear that Jocko, hope you're all okay.

Keep up the mpg. I think we talked about this before, but I noticed in particular that the gauge dropped when the car was parked on the drive, which is a uphill slope.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on August 11, 2019, 11:09:06 AM
My mother-in-law is not keeping well, in fact she was readmitted to hospital yesterday,

It seems with problems it never rains but it pours, hope everything works out OK...
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 14, 2019, 07:00:40 PM
Today I had an unexpected run from Kirkcaldy to Danderhall. Set off about noon, and the traffic for the first half of the journey was light so I was not constrained by keeping up with traffic. Twice, between Kirkcaldy and the M90 at Rosyth, I managed to pop 70 mpg on the ScanGauge Current trip display. Wind and tide were obviously with me. Once I hit the M90. M8 and A720 things changed, and by Danderhall the average was down to 64 mpg.
Mind you, the return journey was a nightmare with a 3 mile stretch in 1st gear! Traffic was murder until I crossed the QFC bridge.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 16, 2019, 03:57:11 PM
Thought I would share a picture of my Fuelly page.
(https://i.imgur.com/0Ghmiub.jpg)

As you can see I have now averaged 59.9 mpg for the past 10 top ups. Almost 4,000 miles
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on August 16, 2019, 04:10:52 PM
Great stuff Jocko. Are you in a position to ascribe this to your 97 Octane experiment yet?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 16, 2019, 04:38:48 PM
I was getting 60 mpg from the couple of tankfuls before I changed. I think it is more to do with the miles I am doing at the moment. I am running between Kirkcaldy and Danderhall, just about every day. About an 80 mile round trip. I have had to increase my annual mileage for my insurance!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on August 20, 2019, 02:49:08 PM
Looks like my fuel consumption has suddenly improved. A month ago a busy weekend of motorway and A road miles gave a dash reading of 47+ over 300 miles. Since I topped up this weekend I've done 150 miles, again mostly A roads and motorway and it's showing 52+ Between I did my usual driving which gave the low 40s figures I've had all along.

I've never seen such good figures in 10 months. Instant readings from the OBDII via my phone suggest the improvement is mostly at steady speeds especially around 30 to 40 mph. I've long wondered if some part of the emissions control was gunked up so perhaps something's working again. The other possibility is I did have to top up with BP 95 fuel rather than supermarket stuff. If that was the cause then it'll be cheaper to stick with it.

I hope to find out after the next tankful, though at this rate it may take longer than usual  :D
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 20, 2019, 04:40:47 PM
That looks good. It will be interesting to see what your Fuelly figures show.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Michaelflat1 on September 02, 2019, 09:40:01 PM
I get between 45 and 55 on my 1.4 SE...

B roads the car likes more than A roads, wish it had a 6th gear.. even giving it some stick and having some fun it can return 48-49mpg it is really a nice cheap way to have fun :P
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on September 02, 2019, 09:49:14 PM
B roads the car likes more than A roads, wish it had a 6th gear.
My findings, exactly.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on September 03, 2019, 09:11:27 AM
6th would be nice. I notice the early 1.4 Civics with the iDSi engine have six gears. I don't suppose you could put one of those in a Jazz?

In other news Fuelly can't tell me about my recent mpg. It came out at 38.3, but then after 100 miles the needle still hasn't come off the end stop! Back to supermarket fuel and the usual shorter trips and the dash mpg meter shows 42.something. Might as well bung BP in next time, just in case.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on September 07, 2019, 10:32:08 AM
I could improve my mpg if I wasn't such a lazy sh^te, and walked to my local Lidl instead of driving.
Today, after one such shopping trip, I checked my figures for today (ScanGauge E).
Distance travelled 0.6 miles
Today's mpg 26.2
Maximum speed 24 mph
Average speed 9 mph
Cost £0.13

The blue light hadn't even gone out. And that is car out of garage, lock garage door, stop at supermarket, do shop, back to garage, open garage door, car back in.

At least now I am not having my Monday to Friday double 3.6 mile trips, to take my wife to and from her work, as she is currently off ill.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on September 17, 2019, 07:13:19 AM
Well, it wasn't the change of fuel that improved my mpg. It dropped back to the usual 43 ish with Asda's finest but another tank of BP made no difference.
As it happens I've been running over to Manchester a lot, about 100 miles round trip. I got over 50 mpg once but last Sunday 45 odd.
So I can only think it's to do with crud somewhere in the emissions control moving about.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on September 18, 2019, 08:11:25 AM
My most recent top up certainly makes it look as if 97 octane makes a difference to mpg. If it wasn't for the first two figures being great as well I would be totally convinced. I'll see what happens when the weather changed, before changing back to 95 octane.

(https://i.imgur.com/s16siNP.jpg)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on September 29, 2019, 12:23:18 PM
A big disappointment when I filled up with petrol this morning. Only 59.9 mpg! I have gotten used to the 60+ numbers for the previous half dozen fill ups.
Last Saturday kind of knocked the stuffing out of my numbers, after taking an hour to crawl 2.5 miles, to pass a non-accident on the Edinburgh City Bypass. My wife said she couldn't even see any damage to the two cars, sitting with the police, on the hard shoulder.
Then at noon I had to run her and her daughter, into the city centre, with numerous light controlled road works in either direction.
Neither event conducive to brilliant mpg.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: sparky Paul on September 29, 2019, 01:50:08 PM
A big disappointment when I filled up with petrol this morning. Only 59.9 mpg! I have gotten used to the 60+ numbers for the previous half dozen fill ups.

Are you still on the 97 octane Jocko?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on September 29, 2019, 02:34:18 PM
Yes. That is now nine tankfuls. My mother-in-law is buying my petrol, while we run back and forward to attend to her, and she can afford it!
As an aside. I passed the Shell station yesterday, and their bog standard, 95 octane, Fuelsave petrol was 10p/litre dearer than the local Morrisons and Asda. That is 45p/gallon dearer or about £3 on my normal tankful. For 95 octane!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Dolph on October 18, 2019, 12:20:20 PM
Hi all, glad to be in this forum. Some of you have awesome mpg. It's also important to specify which Jazz mkl you have. I've both pre and post 2006 facelift, 04 plate is giving me 5-6mpg better difference then 58 plate. The later model is a bit heavier with larger wheel/tyre size. Both have the same engine, transmission etc.
04 plate 47-53mpg on board computer, 45-47 real mpg at the pump.
58 plate 42-47mpg on board computer, around 43-44 real mpg at the pump.
Both running on recommended tyre pressure with 95 Ron petrol.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on October 18, 2019, 01:43:27 PM
A big disappointment when I filled up with petrol this morning. Only 59.9 mpg! I have gotten used to the 60+ numbers for the previous half dozen fill ups.
Last Saturday kind of knocked the stuffing out of my numbers, after taking an hour to crawl 2.5 miles, to pass a non-accident on the Edinburgh City Bypass. My wife said she couldn't even see any damage to the two cars, sitting with the police, on the hard shoulder.
Then at noon I had to run her and her daughter, into the city centre, with numerous light controlled road works in either direction.
Neither event conducive to brilliant mpg.

Indeed. I have a massive variation between my worst ever and best ever mpg figures over 6 years of owning Jazzes. My best is a tad over 57 on my present car but I've been down to 33. Largely because my driving mix is mostly supermarket/grandchild errands with occasional epic trip to Cornwall and/or Scotland. The weather massively influential as well.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on October 18, 2019, 01:53:33 PM
Welcome Dolph. I have the ScanGauge fitted and it records Tank, Day and Current Trip simultaneous. I know it is just an indication, but on a short shopping trip midweek it displayed 19.2 mpg for the day!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on October 20, 2019, 02:18:11 PM
First top up after reverting back to 95 octane and I achieved 59.9 mpg. Not bad considering the huge drop in temperature, wet roads and a regular extra passenger. I am getting 440 - 450 miles before fuel warning light comes on.
All my fuel figures are calculated (Fuelly.com), not from the dashboard display (it reckoned 62.1 this tankful).
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Dolph on October 22, 2019, 12:04:03 PM
Jocko, your fuel consumption sounds great. Yesterday I filled to the top literally, drove 22 miles after the light when on. MPG on the dash board 46,2, traveled distance 322 miles, filled 33,10l to the fuel cap. Fuel consumption 6,4l/100km, keep in mind most driving is on motorway with 70mph.
P.S. It's so frustrating with so much fuel left in the tank for the warning fuel light to go on.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on October 22, 2019, 02:10:07 PM
The tank has a 42 litre capacity, so quite a bit left when the  light comes on. Most of my driving is dual carriageway/motorway, but I drive at an indicated 60 mph, which makes a difference to fuel use. My normal journey is Kirkcaldy to the end of the Edinburgh City Bypass, and return. Going on wind resistance alone, 70 against 60 uses approx a third more fuel (not really as simple as that but a good indication).
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on October 31, 2019, 05:13:50 PM
Fuel figures tumbling in line with the temperature. I think the tarmac temperature makes a huge difference. After a 120 mile, 4 hour drive, when the car was thoroughly warmed up, it still doesn't coast as well as it does in the summer. Whether in gear or in neutral, it still slows down much sooner than it does in the warm weather. I have my known coasting spots so I know it is not just a figment of my imaginations. I even checked the tyre pressures to confirm I didn't have a soft tyre. Mind you, perhaps they don't increase as much as in the warm weather, but after 120 miles you would think they would.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on October 31, 2019, 05:37:01 PM
On tyres, just done my monthly check. All pressures about 2 to 3 psi down from last month. Clearly due to the cold weather.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on November 01, 2019, 08:51:43 AM
On tyres and temperature though I suppose the bulk of the tyre gets to much the same temp the tread is probably colder due to contact with the road. That could mean the compound there is stiffer and gives more rolling resistance. All speculation really.

Meanwhile my mpg is still up and down even when my journeys were much the same. I wonder if it could be duff coil packs. When I changed the rear plugs the gaps were pretty big. Also tickover isn't as even as it was. I've tried disconnecting the low voltage leads one by one but it wasn't conclusive. That's intermittent problems for you. I'll see if I get anything more clear cut today in the damp.

I haven't got the funds to just change parts on the off chance. I know second hand ones are only a tenner on eBay but they'll be pretty old. New at around thirty quid seems a better bet. Of course if anyone knows of cheaper new ones that'd be much appreciated.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on November 13, 2019, 02:02:31 PM
Topped off tank today, when yellow light came on, and I don't believe the numbers. According to the calculations it is 60.1 mpg, but I am convinced that is wrong. Expected a lot lower.
I didn't use my usual supermarket as road works make that a no no, so went to my local Asda instead. Whether their new pumps are set to click off sooner or not, I don't know. I will probably find out the next time I go back to my usual pump at Morrisons.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on November 13, 2019, 03:22:12 PM
I think the click off point on petrol pumps is definitely a thing. I've had some, on the face of it, disappointing figures when I've filled up with Apple Green (Irish fuel company) which is then followed by a really good one when I fill up somewhere else. The pumps at the Apple Green station are ancient as well so don't know if that's a factor.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: MikeKee on November 19, 2019, 07:27:00 PM
Had my 2006 1.4 SE Jazz for about a week.

Using it to commute to work, a 54 mile round trip that involves B-roads, the M1 (for 13 miles each way - so 26 miles) and an A-road.

According to the Trip, I'm getting around 53mpg. Looking forward to applying some tips I've seen here to improve things.

Since I used to do the same journey in a Saab 2.0t convertible, the 53 mpg figure is  quite pleasing regarding my monthly fuel bill :-)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on November 19, 2019, 08:47:27 PM
Welcome, Mike. I had a 2 litre Volvo S40 before the Jazz and I too noticed a huge difference, so I appreciate your delight.
Not to put a damper on your figures, but the trip is a bit optimistic, sometimes more than others. When you fill it up, check your miles against the gallons put in. That will give you an accurate and repeatable number. A good site I use for this is https://www.spritmonitor.de/en/ (https://www.spritmonitor.de/en/) or http://www.fuelly.com/ (http://www.fuelly.com/)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: MikeKee on November 19, 2019, 10:01:58 PM
Hi Jocko

Thanks for the links! Will definitely use them to get an accurate figure.

The Saab was great to drive and brilliant in summer, but the mpg was disastrous!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on November 24, 2019, 12:35:21 PM
Filled up today, and as expected the numbers were well down. 53.6 mpg. However, that is nowhere near as low as I was expecting. Yesterday I had a trip to and from Danderhall, and both ways the rain was coming down in biblical proportions. Traffic was heavy and in some spots very slow (I was down to 3rd ascending the Queensferry Crossing - quite a steep hill in either direction).
The calculated average for the last two tankfuls works out at 59.6 mpg, so perhaps my Asda top up last time was pretty accurate.
My Fuelly average for last 10 top ups has fallen to below 60 mpg, and I don't expect it to recover above 60 until next summer. I will be delighted if I can weather the winter without the 10 top up average falling below 55 mpg!

(https://i.imgur.com/VkQkYLc.jpg)

Also, funnily enough, 59.6 mpg!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: MikeKee on December 07, 2019, 07:50:31 PM
With the Saab I was spending £10 a day to go to and from work. Now I'm spending £6. Result :-)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on December 30, 2019, 07:20:09 AM
Disappointing top up today but I suppose it is only to be expected since I have been tramping round with 4/5 adults (+ luggage) in the car, and this morning I had a 4am high speed motorway run to the airport. This tank full, a calculated 51.1 mpg!
According to Fuelly my last 10 top ups have averaged 56.8 mpg so it looks like it won't be long till I fall below my target 55 mpg which I hoped to maintain throughout the winter. Ah well.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 22, 2020, 10:32:47 AM
Today I used the car to go for rolls. A total distance, there and back, of 0.4 miles (I know I could have walked it, but I wanted to check out my Power Bank - works great), average speed 9 mph and 26.2 mpg, according to my ScanGauge.
Mot exactly helping the planet.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on February 20, 2020, 03:11:11 PM
Disappointing top-up today. 7.6 gallons for 52 mpg. Not surprising I suppose considering the horrendous wind and rain I have been driving in. Not a lot of chance for frugal driving. It has depressed my lifetime average from 55.3 to 55.2 !!!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on February 20, 2020, 04:38:52 PM
These short journeys are killers. Don't have a scan gauge but recently set trip b to measure mpg (computer only) on a return trip, through 4 sets of lights and in busy traffic, to the supermarket. 30.2 mpg so possibly 28 ish in real world. This is 3.1 miles but done in 2 halves as it were.

It's that first mile or so when cold. Occasionally we pick up our grandson from his after school club. This is still stop/start but is a return trip of 8 miles. I haven't done a precise measurement but I can get well north of 40 mpg on this trip even though it involves a lot of stop start and queuing (auto idle stop probably helps here but it doesn't always kick in).

The 39.3 I'm showing at the moment is one fill up after 119 miles (just wanted to get some scores on the board with the new car). Mostly short stuff in bad weather and car nowhere near run in yet.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on March 04, 2020, 11:15:14 AM
Got a really rubbish top up this morning. Morrisons again. The calculated figure was 46.5 mpg but the onboard display read 52.5 and the ScanGauge was similar. It was an early top up as I have a long run this evening and an early trip tomorrow morning. The fuel gauge was still showing more than a quarter tank left, but according to the pump I managed to get 6.9 gallons in at first cut off. According to My SPc chart (Western Electric rules), it is not indicating remedial action required as yet.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on March 05, 2020, 08:29:14 AM
My last fill up went more than a hundred miles before the fuel gauge came off the end stop. No wonder fuelly showed less than 40 mpg.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on March 20, 2020, 08:35:58 AM
This week's top-up was 25% better mpg than last week, for the same usage and weather. Even up on what I have been getting recently.
I can only assume that the pump must have been slow to cut off last fill-up and added extra fuel into the neck. 
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: SPoTpro on April 14, 2020, 03:26:05 PM
I am averaging around 3.9-4.2 l/100km (23km/l-26km/l) with my 1.4CVT 2006 Jazz. (it has 91500km on clock at moment)

Funny thing tho ... my wife gets around 6.2l/100 when she drives ... makes me wonder if she still thinks she is driving her 75kw diahatsu sirion 1.3 lol (used to get 0-100kmh in 8 seconds ... sigh defo not getting anywhere near that with my jazz)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on April 14, 2020, 03:59:41 PM
Great figures. I average 5 l/100 Km over 4 years use.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on April 22, 2020, 09:13:49 AM
Topped up the tank today and the calculated figure was a pleasant 61.4 mpg (Fibometer 63.6 mpg). I decided that since petrol is at the cheaper end of the scale, I will fill up with 97 RON today. £1.107/litre. Almost the entire fuel was used driving into and out of Edinburgh. With the traffic as light as it has been that was a joy rather than a penance.
One of the benefits of such sparse traffic is the ability to slow down at my discretion. There are several gentle descents to 30 and 40 mph limits where with no following traffic I can take my foot of the accelerator and allow the Deceleration Fuel Cut Off to shut off fuel to the injectors. I arrive at the limit, at the posted speed, without having to brake. In traffic, I have to use throttle until much closer to the signs and then use a little light braking, wasting fuel in the process. Over a tankful of petrol all these little things add up, giving numbers I would typically only see in mid-summer.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on May 01, 2020, 08:30:47 AM
I have just done 460 miles in 8 days, and my calculated figure was 61.6 mpg. Again I have filled up with 97 RON.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: DomnicZZ on May 31, 2020, 09:08:48 AM
Hi,
Early April this year, I bought a 2004 Jazz CVT 1.4 SE and was curious to know how much  MPG I could squeeze out of it. Decided to test it on a recent trip from Brixworth with my wife and daughter. Using a pulse and glide technique, and thanks to relatively empty roads, allowing me to freely run slow, around 30-40 MPH. I surprised myself with a 72.7 MPG on the 12 mile trip home. This on a car with 91K miles on the clock. Since I don’t have much of a daily commute, I use Tesco momentum 99octane which is £1.05 a litre at the moment. Not sure if that helped. I haven’t used any extreme hypermiler tricks like overinflating the tyres etc. I did switch off the engine at one-off the two red lights that I encountered.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on May 31, 2020, 10:31:25 AM
Good mpg there. What you should do is check it over a thankful. I top up to the first click off each time and divide the miles travelled between top-ups with this fuel put in the tank. The dashboard display tends to be a bit optimistic (mine is currently indicating 64.5 mpg for the past thankful but I know the calculated figure won't be as good as that).
I have a ScanGauge E fitted and it is a bit more accurate (though not perfect) and I recorded 108 mpg for one short trip, east along the B925 from Mossmorran to Kirkcaldy. It is only 6.4 miles.
A Honda Jazz drove from Land's End to John o Groats on one thankful of fuel and returned 94 mpg.

https://www.theaa.com/about-us/newsroom/fuel-economy-record-attempt (https://www.theaa.com/about-us/newsroom/fuel-economy-record-attempt)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on June 01, 2020, 09:41:27 AM
I topped up this morning. The light wasn't on, but my wife needed something from the supermarket, so I killed two birds.
60.2 mpg over 428 miles. The last time I filled up was the 1st of May. I am using 97 RON at the moment since petrol is so cheap. £1.067/litre or £4.85/gallon for us oldies.
I added a half bottle of Redex Petrol Treatment. Tesco is selling it for £2/bottle.
I also stuck the car through the car wash. Only £6.99 for the premium programme.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: DomnicZZ on June 02, 2020, 09:21:20 PM
Thanks for Your Response Jocko. I’m new to the forum here and see that you’ve contributed a wealth of info. Sure will come handy. I did a tankful of momentum 99 (32L for £35 or so). First time ever I did a complete fillup till it clicked off. It maybe a month or two before I finish this tankful, but I expect prices to rise slowly now that lockdowns are easing, so it’s ok. My MPG currently reads 56 .I notice that I tend to get the highest MPG at around 30-40 MPH as opposed to around 55mph. I need to perfect the pulse and glide technique more.

Domnic
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on June 02, 2020, 09:55:44 PM
Domnic. Keeping your speed down certainly helps but for cruising I find 53 mph the best speed.  I find the i-DSi engine great at low revs and I use 5th from very low speeds. Most of my driving is either 5th or 3rd. I seldom use 4th. You don't have that option with the CVT. I regularly switch off at traffic lights. If I know I am going to be sitting for more than 6 or 7 seconds then the engine's off (you get to know the lights in your local area). I don't really pulse and glide but I do coast in neutral when I can. I also make great use of Deceleration Fuel Cut Off or DFCO. On downhill sections get your foot right off the accelerator, not just eased back. I have a ScanGauge E and that displays instantaneous fuel consumption as well as journey average. It plugs into the OBD 2 port.

(https://i.imgur.com/qV2N6DN.jpg?1)

The mpg figure beside my avatar is my average mpg since buying my Jazz in 2016 using spritmonitor .de

https://www.amazon.co.uk/ScanGaugeE-Ultra-Compact-Automotive-Computer/dp/B004SK5I46/ref=sr_1_2?dchild=1&keywords=scangauge&qid=1591130473&sr=8-2 (https://www.amazon.co.uk/ScanGaugeE-Ultra-Compact-Automotive-Computer/dp/B004SK5I46/ref=sr_1_2?dchild=1&keywords=scangauge&qid=1591130473&sr=8-2)
(https://images-na.ssl-images-amazon.com/images/I/71bI4DVm3gL._AC_SL1500_.jpg)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: DomnicZZ on June 04, 2020, 03:23:39 PM
Thanks Jocko! I’ve seen the links for the scangauge ,I’ll look to get one of those in the future , but until then was hoping to be able to use one of the Bluetooth ones with a spare Android I have. If it’s only displaying what’s available at the port hopefully it should be as accurate as scangauge. As for the pulse and glide, I tend to do that on roads with gentle gradients, so speed up before the downhill so I can roll down with my foot off the accelerator. I tend to keep my foot over the brake when not accelerating. May help me react faster incase of an emergency.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on July 06, 2020, 10:12:16 AM
Yesterday I was low on petrol, but I went over to the south of Edinburgh anyway as I figured I had enough. The ScanGauge reckoned I had 140 miles left and the journey was about 80.
As I started back, I sprinted around the Sheriffhall roundabout (to catch the green lights), and the low fuel light came on. A quick check of the ScanGauge said 100 miles left and I only had 40 miles to go.
This morning I topped up the tank. The manual says Jazz holds 9.2 Imperial gallons and top up took 7.8 gallons. That means I had 1.4 gallons left and at the 61.7 mpg, this tank full returned I still had enough for a further 86 miles. That means the low fuel light came on with about 125 miles left in the tank.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on July 08, 2020, 12:02:03 PM
I'd been barely getting 40 mpg, quite a bit of pinking and flat spots so I decided to change the spark plugs. Since I'm keeping Bob the Jazz a good while I treated her to some iridium plugs. Flat spots and pinking gone and even on my short dog walking trips the dash shows 47 mpg. I suspect the better spark from the iridium plugs is making the difference.

What was striking was the plugs that came out (photos attached). Looks like only one of the rear coil packs was giving much of a spark. I wish now I'd kept close look on what I was doing as I don't know which is the good one. I had actually fitted a secondhand set of coils got cheap on eBay. Now I've put back the originals as they're younger though still suspect as the rear plugs weren't changed when I got the car. Now I'm tempted to get some new coils. If they got me 2 mpg more they'd pay for themselves in a year or so. At least if I get cheapest ones - there's a bewildering array of brands and prices with no idea if any are better than another.

Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on July 08, 2020, 12:28:02 PM
Hitachi are supposed to be the ones to get AFAIK.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on July 08, 2020, 02:46:56 PM
Thanks. That's what my original ones are but I can't find any on eBay. No name ones  are from £50 a set, £100 gets brands I've never heard of like WAI and Lemark. Looks like pure guesswork to me.

EDIT AutoDoc looks hopeful
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on July 08, 2020, 04:11:59 PM
I'd been barely getting 40 mpg, quite a bit of pinking and flat spots so I decided to change the spark plugs. Since I'm keeping Bob the Jazz a good while I treated her to some iridium plugs. Flat spots and pinking gone and even on my short dog walking trips the dash shows 47 mpg. I suspect the better spark from the iridium plugs is making the difference.

What was striking was the plugs that came out (photos attached). Looks like only one of the rear coil packs was giving much of a spark. I wish now I'd kept close look on what I was doing as I don't know which is the good one. I had actually fitted a secondhand set of coils got cheap on eBay. Now I've put back the originals as they're younger though still suspect as the rear plugs weren't changed when I got the car. Now I'm tempted to get some new coils. If they got me 2 mpg more they'd pay for themselves in a year or so. At least if I get cheapest ones - there's a bewildering array of brands and prices with no idea if any are better than another.



If the engine is behaving well and no pinking, hesitation or flat spots why do you need to change coils ????

Can you measure the gap on the spark plugs - that is the clearest indication to how long they have been in the engine as they wear due to 'spark erosion' of the electrodes...

The Iridium plugs do produce a more concentrated spark due to the smaller diameter of the electrodes and because of the toughness of the Iridium will maintain the gap for many more miles ( IIRC 70,000 is the figure for MK2 Jazz and Civic - which do come from factory with Iridium plugs as OE ).
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on July 08, 2020, 06:13:29 PM
That's a good point.  It seems to me the coils don't simply fail all or nothing, otherwise I  would have got an error code for a misfire. My guess is when the rear spark plugs are left in too long the higher  voltage before a spark forms across the bigger gap stresses the insulation in the coil. The smaller tip on iridium plugs mean the gasses ionise at a lower voltage so are kinder on the coils. That was part of the reason for making the change (the other being I won't need to do it again till 200k miles). So I should at least see if it works.

Or in other words if it ain't broke, don't fix it.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jazzmeister on July 21, 2020, 07:04:06 PM
I'd been barely getting 40 mpg, quite a bit of pinking and flat spots so I decided to change the spark plugs. Since I'm keeping Bob the Jazz a good while I treated her to some iridium plugs. Flat spots and pinking gone and even on my short dog walking trips the dash shows 47 mpg. I suspect the better spark from the iridium plugs is making the difference.

What was striking was the plugs that came out (photos attached). Looks like only one of the rear coil packs was giving much of a spark. I wish now I'd kept close look on what I was doing as I don't know which is the good one. I had actually fitted a secondhand set of coils got cheap on eBay. Now I've put back the originals as they're younger though still suspect as the rear plugs weren't changed when I got the car. Now I'm tempted to get some new coils. If they got me 2 mpg more they'd pay for themselves in a year or so. At least if I get cheapest ones - there's a bewildering array of brands and prices with no idea if any are better than another.
I can't see the gap but even those rear sprakplugs don't look too bad barring some mild fouling.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on July 22, 2020, 10:17:59 AM
Agreed. I felt the poor running suggested a weak spark so swapping the plugs seemed a reasonable first step. The gap was fine, the canonisation on the insulation was the worry. A little extravagantly I've put new coils in. Yesterday in fact.

It's too early to know the effect on mpg but I have realised there used to be a slight vibration through the steering wheel on tick over which is gone.

To confuse matters even more it seems I had a rear brake sticking, maybe only for the last week or so. That is now fixed so I hoping for good things.   

Certainly seems to run nicely now.

Anyone any ideas what I can do with a load of slightly worn coils and plugs  ::)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on July 22, 2020, 11:40:17 AM
Today is my 4th anniversary of owning the car and part of the process is topping off the tank. It was a short fill up as I had only done 283 miles on this tankful. The mpg figure was 59.6 compared with 61.8 on the Fibometer. I have averaged 55.5 mpg for the 40,070 I have completed since purchasing the car.
For the past year, I have averaged 215 miles per week and a cost per mile of £0.16p.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on July 22, 2020, 02:41:30 PM
Great stats. I bet not many Jazz (or Fit) owners will have bettered these.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: DomnicZZ on July 22, 2020, 08:12:33 PM
Jocko. You are the undisputed MPG king!!!

I finished my first full tank at 49 MPG (52.7 Fibo) Took me almost 2 months to complete, as I don't drive much. I still think 49 is decent for a 16 yr old CVT. I attribute a lot of it to using my bike for short journeys when I'm travelling alone. Good for environment and health.

I've used momentum99 in the last tank. This time I've used regular unleaded but popped in some redex. Not sure if it helps but at 2 quid a bottle,  I'm happy to pay for the placebo effect  once in a way.  :)

Next upgrades will be changing to 0W30 oil, and some molybdenum disulphate that I know of thanks to this forum.

Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on July 22, 2020, 08:59:36 PM
Next upgrades will be changing to 0W30 oil, and some molybdenum disulphate that I know of thanks to this forum.
I use 5w-30 and recently have topped up with 10w-40. I do use Redex, now and again. My ScanGauge E has paid for itself, giving me a clear understanding of what works and what doesn't when it comes to fuel saving.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on July 22, 2020, 09:29:17 PM
Jocko. You are the undisputed MPG king!!!

I finished my first full tank at 49 MPG (52.7 Fibo) Took me almost 2 months to complete, as I don't drive much. I still think 49 is decent for a 16 yr old CVT. I attribute a lot of it to using my bike for short journeys when I'm travelling alone. Good for environment and health.

I've used momentum99 in the last tank. This time I've used regular unleaded but popped in some redex. Not sure if it helps but at 2 quid a bottle,  I'm happy to pay for the placebo effect  once in a way.  :)

Next upgrades will be changing to 0W30 oil, and some molybdenum disulphate that I know of thanks to this forum.



Redex or similar even more important on low annual mileage cars, whatever you do don't put MoS2 in CVT box  :o - OK in engine though ( in fact the Honda Jazz piston skirts are already coated with MoS2 - molybdenum disulphide as part of friction reducing, together with roller bearings in tappets, cam followers etc. ). 

Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on July 23, 2020, 11:58:56 AM
The low mileage cars thing is something I ponder over - my annual mileage is around 3,000 and a lot of that is urban stuff. Even without any engineering background it seems common sense to me that carbon and other deposits will build up quicker in an engine that spends rather too much of its time below operating temperature.

I guess the issue is whether a tank of V Power (or similar) every other tank will have the same effect as an additive.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on July 23, 2020, 02:23:00 PM
I have said before, I have run umpteen cars on supermarket fuel and never put a drop of Redex in any of them, and never had the least bother. I have had cars that ran 5 miles to and from work every day and others that did 80 miles, mainly motorway, to and from work every day. I have sold cars on with 200,000 miles plus on the clock and never had engine problems. Now if V-Power and Redex stopped them rusting, then I would be interested.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Derkie54 on July 23, 2020, 04:17:37 PM
The low mileage cars thing is something I ponder over - my annual mileage is around 3,000 and a lot of that is urban stuff. Even without any engineering background it seems common sense to me that carbon and other deposits will build up quicker in an engine that spends rather too much of its time below operating temperature.

I guess the issue is whether a tank of V Power (or similar) every other tank will have the same effect as an additive.

Like you my annual mileage is low, and like you I have recently bought a shining grey Mk3.
I can accept everything Jocko says but for the mileage I do I'm happy to put some V Power in if it keep the engine cleaner and the carbon deposits down.......well that's what they claim !!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on July 23, 2020, 04:22:27 PM
I have said before, I have run umpteen cars on supermarket fuel and never put a drop of Redex in any of them, and never had the least bother. I have had cars that ran 5 miles to and from work every day and others that did 80 miles, mainly motorway, to and from work every day. I have sold cars on with 200,000 miles plus on the clock and never had engine problems. Now if V-Power and Redex stopped them rusting, then I would be interested.

I do use Redex, now and again.

If redex will 'melt' the petrol residue off old bike carburetor  that has been building up for ages ( makes you realise how dirty petrol really is ) I am not against putting it into petrol tanks on bikes and cars ( and even keeps lawnmower running sweet,  and it actually starts in the spring without the carb needing a strip down ),  its cheap enough - now if it was as expensive as printer ink  :o ( weight for weight the most expensive stuff on the planet ).
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on July 23, 2020, 04:27:16 PM
I have said before, I have run umpteen cars on supermarket fuel and never put a drop of Redex in any of them, and never had the least bother. I have had cars that ran 5 miles to and from work every day and others that did 80 miles, mainly motorway, to and from work every day. I have sold cars on with 200,000 miles plus on the clock and never had engine problems. Now if V-Power and Redex stopped them rusting, then I would be interested.

I do use Redex, now and again.

If redex will 'melt' the petrol residue off old bike carburetor  that has been building up for ages ( makes you realise how dirty petrol really is ) I am not against putting it into petrol tanks on bikes and cars ( and even keeps lawnmower running sweet,  and it actually starts in the spring without the carb needing a strip down ),  its cheap enough - now if it was as expensive as printer ink  :o ( weight for weight the most expensive stuff on the planet ).

Good point about printer ink. To replace the ink cartridges in my HP Ink Jet printer is around £30 (for the colour and the black). I paid £35 for the printer. It's the equivalent of petrol being £1000 a gallon - probably more!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 18, 2020, 12:11:13 PM
Filled up this morning, and as is my practise I reset the trip (only one on the Mk1).
I returned home from the supermarket then took out cat to the vet in Dalkeith, a 90-mile round trip (don't ask).
On my return, the "Fibometer" was indicating 73.4 mpg.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on September 05, 2020, 06:48:41 PM
I topped the tank up today. Supermarket 95 RON. The light hadn't come on, but I have a few miles planned so thought I might as well fill up. I had covered 466 miles since the last top-up, the "Fibometer" was saying 64.6 mpg, and Fuelly's calculated figure was 62.0 mpg. This is my best figure during the previous 12 months.
The "Fibometer" was only 4.2% optimistic.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: DomnicZZ on September 05, 2020, 07:33:04 PM
Amazing figures Jocko. This tank I started off rather well, maintaining 60 on the Fibo for the first 100miles,  thanks to longish country road trips and 40psi in the tyres. I've since lowered my tyres to 36psi front and 32 rear (experimentation). I'm now hit with the 1.5 mile school run which has been a disaster to my MPG, brought me down to 54 on the fibo, so I've lost hope of reaching last tanks figure.  In the colder months to come, I figure I'll be lucky to get above 50.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on September 05, 2020, 08:18:07 PM
I run my tyres at 35 front and back. Even on the school run, don't be afraid to get it into 5th. I am usually in 5th or 3rd around town. Seldom use 4th. And try and make as much use of DFCO as possible.
The figure beside my avatar is my average miles per gallon since I bought the car. Four years and 41,000 miles.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on September 06, 2020, 08:30:47 AM
The new rear coils seem to have improved fuel consumption. It's hard to be exact, my figures on Fuelly still vary widely (I think the pump cut off can make about 10 litres difference on what's in the tank) but my 3 month average is up to 45 so about 3 mpg more.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: DomnicZZ on September 08, 2020, 06:55:16 AM
I run my tyres at 35 front and back. Even on the school run, don't be afraid to get it into 5th. I am usually in 5th or 3rd around town. Seldom use 4th. And try and make as much use of DFCO

Mines a CVT, so if I want to force an upshift I just lift my foot off the gas for a couple of seconds and gently press again. I notice it already uses the tallest gear ratio By 30MPH on flat roads.

I’ve run some stats on the school run yesterday using car scanner so I can better understand the vehicle behaviour. The middle gap in the graph is where I got out to pick up my kid. The gaps in the instantaneous MPG hopefully represent DFCO. I do not know the accuracy of the car scanner app yet, but will hopefully find out over time.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jazzmeister on September 09, 2020, 08:54:19 PM
I have asked this elsewhere but this is a very busy thread so I'll post it here as well:
Does having a non standard wheel/tyre size have any influence on the onboard computers calculations?
My tyre is a 185/65/15, which is a 2.1% larger circumference than stock 175/65/15
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on September 09, 2020, 09:40:01 PM
It must do. There is no way the ECU knows the tyre size.
My ScanGauge E allows me to calibrate its speed against the GPS. Knowing the speed calibration, it can calculate the distance correctly.
Also with The ScanGauge, you input a correction factor for its calculation of how much fuel you put in to fill the tank compared to the actual fuel added. The secret here is to add or subtract HALF the difference, and over a few top-ups, you get pretty accurate. Now the ScanGauge is generally within 0.1 gallons against the actual. So I leave it as it is.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jazzmeister on September 09, 2020, 10:29:08 PM
It must do. There is no way the ECU knows the tyre size.
My ScanGauge E allows me to calibrate its speed against the GPS. Knowing the speed calibration, it can calculate the distance correctly.
Also with The ScanGauge, you input a correction factor for its calculation of how much fuel you put in to fill the tank compared to the actual fuel added. The secret here is to add or subtract HALF the difference, and over a few top-ups, you get pretty accurate. Now the ScanGauge is generally within 0.1 gallons against the actual. So I leave it as it is.
What data exactly does the onboard computer use to make it's calculations?
I saw someone mention somewhere on the forum that the OBC uses the amount of time the injectors are open to calculate the fuel usage, does it then compare that to the odometer mileage to come to it's finding on historic fuel usage?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: DomnicZZ on September 10, 2020, 06:03:43 AM
My 2 cents on this bigger tyre impact.
Let's say it's 2percent bigger circumference, over 100 miles reported on the odometer, you would have actually travelled 102 miles. The ECU does not know this. MPG calculations are based on odometer reading, so in theory it shouldn't impact. In practice though, the car would have worked 2 percent harder over the reported 100 miles, so you may see a minor dip in MPG on the display. But since you know you've traveled the extra 2 miles. You can calculate to compensate for this dip. In real life though, there are more MPG impacting factors like traffic,  road surface, weather etc, so unless testing on a dyno in a controlled environment, it will be hard to detect.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: TnTkr on September 10, 2020, 06:37:35 AM
And the odometer isn't 100% accurate with the factory tires either...

It is not sure if larger diameter increases or decreases the absolute fuel consumption as it effectively changes the ratio making engine running lower rpm. It depends where on the engine specific consumption diagram is the current operating point.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on September 10, 2020, 06:54:42 AM
Unless you do mpg testing using a 5th wheel and measured amounts of fuel it is all just approximate anyway. I calculate my mpg from when the pump first trips off, but who is to say that always happens at the same point. Fill up, calculate your mpg, and that's your number. Suppose it is +/- 0.2 mpg, who cares. You know if it is better or worse than expected, which is the main thing.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: TnTkr on September 10, 2020, 07:44:54 AM
Unless you do mpg testing using a 5th wheel and measured amounts of fuel it is all just approximate anyway.
Exactly, that was my point too!

The accuracy of the fill-ups improves through time when calculating total miles and total amount of fuel.

I have a habit to fill up until the fuel surface is visible on the filler neck. In Jazz that makes only 1-2 liter difference, but in some other cars it may be even 5 litres.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on September 10, 2020, 08:59:19 AM
In real life though, there are more MPG impacting factors like traffic,  road surface, weather etc, so unless testing on a dyno in a controlled environment, it will be hard to detect.

Exactly, which is why I cannot understand why people need to calculate their MPG to two decimal places... ( or even one decimal place )
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: TnTkr on September 10, 2020, 09:05:03 AM
Maybe the two decimals are needed to get better results than the neighbor  ;D
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on September 10, 2020, 11:19:22 AM
Exactly, which is why I cannot understand why people need to calculate their MPG to two decimal places... ( or even one decimal place )
Both Fuelly and spritmonitor automatically generates one decimal place. My ScanGauge E requests one decimal place on input.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on September 18, 2020, 03:43:26 PM
At 59 mpg today's top-up was the worst since the beginning of April. I knew that as soon as I started running my wife back and forward to work the fuel economy would suffer.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on September 18, 2020, 04:38:16 PM
Still outstanding Jocko.

Reckon you'd get close to 80 mpg with the Mk4 Jazz.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on October 12, 2020, 10:39:33 AM
Today's mpg was a rather disappointing 52.2. That is since I started the daily commute, taking my wife the 3.6 miles to and from her work and also with the lower road temperatures and increased amount of wet days.
My last 10 Fuelly top ups had averaged 60.2 but now it is down to 59.7. It will only go lower as the winter progresses.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on October 12, 2020, 12:09:38 PM
I still think that's good for these short trips. Far in excess of anything I've got.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: dnloreto on October 20, 2020, 10:48:09 AM
My 2007 1.2 Cool does a bit different depending on city only or 50%highways/50%city.

Only city I get as bad as 37mpg (6,3l/100km) with trips of 45m of medium to heavy traffic. Sometimes small low traffic trips of 15m (cold engine most of the time).
If I mix I get 42,7mpg (5,5l/100km) or better. Highway done between 62mph and 80mph (100km/h and 130km/h).

I usually have the air con on at least sometimes (to demist screen) but if too cold or hot, it will be on all the time.

All readings from the car's dash.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Paul22118 on October 20, 2020, 05:07:45 PM
Honda Jazz 59 plate 1.4 i shift = 49.5mpg
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on October 25, 2020, 06:14:49 PM
Rather surprised to find that my actually mpg this tankful was better than the "Fibometer" said. "Fibometer" reckoned 58.1 mpg, so I thought I probably managed about 53 - 54, but it actually calculated out at 59.7. I checked my figures out a couple of times in case I had made a mistake with the odometer reading, but no, it was the correct figures.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: John Ratsey on October 25, 2020, 10:27:00 PM
Slight differences in the fuel level when you stopped filling?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Si Crewe on October 29, 2020, 01:30:05 PM
Only just discovered that the Jazz has a fuel-consumption doodad.  :-[
I thought the twiddly bit in the gauge cluster was just for adjusting the instrument lights.
Ironically enough, the one thing I immediately noticed about the Jazz was that it didn't seem to have a trip-meter... which is, apparently, also accessed via the same control.

Anyway, based on the 785 miles my Jazz had done since the last time anybody reset the trip-meter, it was showing 52.2 MPG.

Having reset the trip-meter, I wondered what sort of MPG figures I'd get, given that most of my driving is in towns, on twisty B-roads and even the A-roads around here are rather hilly.

I was quite chuffed to find that I was getting around 45 MPG, even while driving locally.
Been commuting around 30 miles this week (60 mile round-trip) and fuel-consumption quickly regained 52 MPG, despite the fact I've been going up and down through the gears on B-roads and working the engine to overtake lorries and climb hills.

Very impressed.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on October 29, 2020, 04:37:32 PM
Good figures. Be aware that the "Fibometer" as we refer to it is a bit optimistic. I find mine about 4% high but if your's is the same that is still 50 mpg.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Halminator on November 06, 2020, 09:38:49 AM
I live in The Netherlands and drive a 2005 1.2 Cool. First of all, I drive relatively like a grandpa. For me driving is something I enjoy and most of the time is relaxes me (when the road isn't gridlocked and filled with agressive morons).

The highest I ever got was in the heat of summer: 63,6 mpg. Now, while it's getting colder, I'm getting about 50,8 mpg.

Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on November 06, 2020, 02:33:25 PM
Good figures. Pretty well mimics mine, as does your driving style.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Ramon1234 on November 06, 2020, 07:40:05 PM
I live in The Netherlands and drive a 2005 1.2 Cool. First of all, I drive relatively like a grandpa. For me driving is something I enjoy and most of the time is relaxes me (when the road isn't gridlocked and filled with agressive morons).

The highest I ever got was in the heat of summer: 63,6 mpg. Now, while it's getting colder, I'm getting about 50,8 mpg.

Wait you mean there are some roads without agressive morons? Where? :)

For now my best on the jazz indicator is 4.5 L/100 km. 4.7 or 4.8 if its crowded with cars. Tried to do better but so far never went down that number.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on November 07, 2020, 07:51:35 AM
I make 4.5 l/100km = 63 mpg. I've been averaging about 44 mpg 6.4 l/100km recently. Is the 1.2 so much better than the 1.4?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Halminator on November 07, 2020, 10:40:16 AM
I make 4.5 l/100km = 63 mpg. I've been averaging about 44 mpg 6.4 l/100km recently. Is the 1.2 so much better than the 1.4?

Perhaps it depends on where you drive. The 1.2 does not have an excess of power, so maybe a lot of highway miles where the car has to work hard may not be the most efficient?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on November 07, 2020, 12:01:44 PM
I get excellent mpg on highway miles with my 1.2 DSi. My best for highway driving is 69.9 mpg for a 234-mile trip.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jazzmeister on November 07, 2020, 12:55:29 PM
When you blokes us the term MPG is that using US gallons or the so called Imperial gallons?
There's quite a difference and that would explain how dumbfounded I have been with the figures that get mentioned on this thread, seeing I have been assuming they are US gallons, well not me but Google...
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on November 07, 2020, 04:33:07 PM
The UK measurement is Imperial gallons and this is a UK site so yes, Imperial gallons. Don't know why the US went for a different measurement.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jazzmeister on November 07, 2020, 06:18:55 PM
The UK measurement is Imperial gallons and this is a UK site so yes, Imperial gallons. Don't know why the US went for a different measurement.
Both of you lot are weird for still using gallons and miles

Either way it's a relief to hear because I was going batty wondering how the hell you guys were getting such beyond incredible fuel economy, that was due to google using Us gallons to make the conversation to the far superior and civilized metric system
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on November 07, 2020, 09:08:40 PM
We buy our petrol by the litre. One of the hangovers from the Common Market as the EU once was. As gallons got dearer the petrol companies thought litres would fool the UK motorist into thinking it was cheaper.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on November 08, 2020, 04:56:35 PM
I looked it up on Wikipedia (https://en.wikipedia.org/wiki/Gallon). Seems it all got put into law around the start of the 19th century. The only problem with the civilised and rational metric system is that it was developed by the revolutionary French. Still there were already two different gallons widely used for trade. The US adopted the wine gallon while the British went for the bigger ale gallon. See what a mess you get into making decisions based on national pride  ;).

What's always amazed me is the Americans made it to the moon using miles, inches, foot-pounds of thrust and god know what else to make life extra hard for their human computers. In the 70s when I did my science degree in the UK we were entirely metric. Thank goodness.

Still I have always done baking in ounces and pints. Similarly miles per (imperial) gallon is oddly comforting.

Having logged just over 20,000 miles on Fuelly I'm happy to say my 6 month average is up to 45mpg, 6.28l/100km.
Oddly for the last 3 tanks the dashboard display has agreed very closely with the measured value.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on November 08, 2020, 05:44:12 PM
I looked it up on Wikipedia (https://en.wikipedia.org/wiki/Gallon). Seems it all got put into law around the start of the 19th century. The only problem with the civilised and rational metric system is that it was developed by the revolutionary French. Still there were already two different gallons widely used for trade. The US adopted the wine gallon while the British went for the bigger ale gallon. See what a mess you get into making decisions based on national pride  ;).

What's always amazed me is the Americans made it to the moon using miles, inches, foot-pounds of thrust and god know what else to make life extra hard for their human computers. In the 70s when I did my science degree in the UK we were entirely metric. Thank goodness.

Still I have always done baking in ounces and pints. Similarly miles per (imperial) gallon is oddly comforting.

Having logged just over 20,000 miles on Fuelly I'm happy to say my 6 month average is up to 45mpg, 6.28l/100km.
Oddly for the last 3 tanks the dashboard display has agreed very closely with the measured value.

Problem with metric system it is too simple, no food for the brain, many of our best scientists bought up on imperial system.  Reason Japanese and Chinese so clever is that their language is so absolutely difficult to learn, likewise  metric system leads to lazy thinking..... just move the decimal point around.....
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on November 08, 2020, 08:11:22 PM
Not just miles. I was brought up on Rods, Chains and Furlongs. My brother spent a summer as a Chain Boy as they built the first section of the M90.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest4871 on November 09, 2020, 01:08:55 PM
I looked it up on Wikipedia (https://en.wikipedia.org/wiki/Gallon). Seems it all got put into law around the start of the 19th century. The only problem with the civilised and rational metric system is that it was developed by the revolutionary French. Still there were already two different gallons widely used for trade. The US adopted the wine gallon while the British went for the bigger ale gallon. See what a mess you get into making decisions based on national pride  ;).

Expanding on the Wikipedia entry, the English American Colonies used (naturally) English weights and measures. After the War of Independence in 1777 they continued to do so.

So when the British decided to standardise their weights and measures in 1824 to Imperial Measurements the United States of America, being independent, had no cause to change and have thus continued to use old English measures.

The standardisation of the gallon in each country would have been based on custom and practice of the time.

Not much beer would have been imported into the USA as beer needed to be consumed close to its point of consumption because of its short shelf life due to its lower alcoholic (preservative) content. Wine would have been imported into the USA because it had a higher alcoholic content, thus a longer self life and could travel well and improve with age. This was also true of some very strong beers like Guinness Foreign Extra Stout (which also improved with age) and Carlsberg Export although these (and only recently) are now pasteurised. More beer was consumed in UK than wine so that was a natural choice of measure. More wine was imported into the USA, so that was a natural choice.

When UK adopted the metric system many items stayed the same but the stated measurement changed, so a 12oz jar of jam became a 340g jar of jam. Same jar of jam. There are many other examples. Milk is sold as 2.2litres in a 4 pint bottle. People don’t really go out to buy 340g of jam or 2.2 litres of milk.

The same principle applies to shoe sizes which are measured by grains of corn. The measurements differ between UK and USA because different grains were being used. Each system now has a standardised but different grain size.
Much of things in America follow the pre independence old English style. So what we call pavements, they call sidewalks and what we call roads they call pavements. Americans call corn what we call maize. All of which has some logic.

English English is a constantly changing language. American English is much more conservative and continues to use English in its unevolved way including its use of old English spelling (like standardized).

I see the Oxford Concise English Dictionary has changed the definition of Woman.

The world keeps spinning.



Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: madasafish on November 09, 2020, 01:39:57 PM
I looked it up on Wikipedia (https://en.wikipedia.org/wiki/Gallon). Seems it all got put into law around the start of the 19th century. The only problem with the civilised and rational metric system is that it was developed by the revolutionary French. Still there were already two different gallons widely used for trade. The US adopted the wine gallon while the British went for the bigger ale gallon. See what a mess you get into making decisions based on national pride  ;).

What's always amazed me is the Americans made it to the moon using miles, inches, foot-pounds of thrust and god know what else to make life extra hard for their human computers. In the 70s when I did my science degree in the UK we were entirely metric. Thank goodness.

Still I have always done baking in ounces and pints. Similarly miles per (imperial) gallon is oddly comforting.

Having logged just over 20,000 miles on Fuelly I'm happy to say my 6 month average is up to 45mpg, 6.28l/100km.
Oddly for the last 3 tanks the dashboard display has agreed very closely with the measured value.

Problem with metric system it is too simple, no food for the brain, many of our best scientists bought up on imperial system.  Reason Japanese and Chinese so clever is that their language is so absolutely difficult to learn, likewise  metric system leads to lazy thinking..... just move the decimal point around.....

I trained as a physicist and we did everything in metric.

Physics is hard enough in metric, KISS>
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on November 10, 2020, 07:25:45 AM
Quote
I trained as a physicist and we did everything in metric.

Physics is hard enough in metric, KISS>

So did I and I thoroughly agree.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on December 01, 2020, 07:32:46 AM
Topped up the tank this morning and FE was 51.2 mpg. Not too bad considering I have four new all-weather tyres and I had my "Italian Tune-up" earlier in the tankful. I'll have to monitor my consumption over the next few tanks of fuel and see how it settles. The winter weather won't help.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on December 10, 2020, 08:55:48 PM
Very disappointing top-up today. 47 mpg. Not the worst I have had - that was 46 mpg - but pretty rubbish. Hope it starts to improve as the All-weather tyres start to wear.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: DomnicZZ on December 12, 2020, 02:49:17 PM
Jocko, you’ve reached my summer MPG levels now! . I haven’t been driving much, my mid October fill up is only half consumed, but the MPG readout is down to 45. I  did a 20 mile Italian tuneup in ‘S’ gear  which may have helped me clear MOT this morning. It’s the combination of short tips and cold weather that’s killing it for us.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on December 12, 2020, 02:59:26 PM
The equivalent top up last year (one day different) was 58 mpg, so you can understand why I am disappointed. I always calculate my mpg using Fuelly, as I find the dashboard display optimistic. The other day's top-up showed 49.4 on the "Fibometer".
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on December 21, 2020, 07:18:27 AM
The yellow light came on today, so I refilled my tank. 53.6 mpg. Now that's a bit better. Must be wearing the sharp edges off the new tyres.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on December 29, 2020, 08:13:55 AM
After filling the tank on the 1st of December, today was the third time this month I have had to refill it. I have covered 1,140 miles this month adding 22.6 gallons to the tank. That equates to 50.4 mpg, so I have still eked out a reasonable mileage figure despite the lousy weather and my relatively inefficient all-weather tyres. I don't feel so bad now I see it in numbers.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 08, 2021, 10:57:03 AM
Decided to give up on my quest for great mpg. The new tyres make it difficult and the last few days I have been running the engine to keep warm while waiting on my wife finishing her work. A no no in the search for good numbers.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on January 08, 2021, 05:11:14 PM
Think your mpg is still exemplary even with the new tyres and winter weather. Given the small mileage I do, I'm not quite sure why I still obsess about mpg. As I have said many times before I am just a sucker for pie charts and graphs!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: MartinJG on January 09, 2021, 11:16:51 PM
Decided to give up on my quest for great mpg. The new tyres make it difficult and the last few days I have been running the engine to keep warm while waiting on my wife finishing her work. A no no in the search for good numbers.

Jocko. Careful now. I am reminded of the time an ex army officer visited our school to talk about his experiences in WW2 and his time in a POW camp in mid Europe. It was a bitterly cold winter and rations and provisions were scarce despite the Geneva Convention to the extent that it was considered a privilege to clean out the German Officer's toilets for any undigested scraps such as sweet corn etc. The most striking story was the fire in the middle of the camp. The fatal mistake was to give in to the cold. If you could wrap up and stay on the outer perimeter you would have a good chance of getting through the freezing conditions. The moment you gave in and started inching closer to the fire was the beginning of the end. For those could not resist, the laws of diminishing returns kicked in and the closer they got, the lower the resistance and the more warmth they craved until they were virtually in the fire and that was usually the end. Never forgotten that account. However, in your case, I think staying warm is quite the smartest thing to do, all things considered... :)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 10, 2021, 10:58:52 AM
The warm car is warmer than the house. Yesterday we had two electric fires in the living room and one in each bedroom. Thankfully today is a lot milder.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on January 10, 2021, 11:01:53 AM
Quote
Decided to give up on my quest for great mpg.
My world is reeling  :-X
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 10, 2021, 07:23:01 PM
Topped up today though and still managed to top 50 mpg, calculated.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: DomnicZZ on January 15, 2021, 08:49:23 AM
I topped up a couple of days back. calculated UK MPG was 41. - my lowest Yet - dropped my average to 45.4 MPG.
The saving grace is that this tank has lasted me 3 Months - Thanks to Lockdowns.

At this rate of fuel consumption - Vehicle Tax will cost me the same as fuel!

Expanding on that thought - If I consider the other car related costs - Oil/Filters/MOT/TAX and Insurance - The cost of fuel is less than a third of my overall TCO!

I'll still monitor my MPG (And obsess over it - I think it makes me a more eco conscious and safer driver)

 @Jocko - don't give up on your quest for great figures! you've been an inspiration to many!!

Cheers!



Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 15, 2021, 10:10:45 AM
@Jocko - don't give up on your quest for great figures! you've been an inspiration to many!!
Thanks. I will still keep trying to squeeze as much out of a tankful as I can manage.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on January 15, 2021, 02:08:50 PM
Think I'm on target for my lowest ever mpg. I've done 135 miles since November 30th - an average of less than 3 miles per day. Average speed 12 mph. A fair bit of idling as I wait for windscreens to clear. The fibometer is showing 34.6 which I reckon will be about 31 mpg.

On the plus side I may not need to refuel until March!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 15, 2021, 04:10:05 PM
With my running my wife back and forward to work five days a week, and sitting with the engine running to warm the car up, while I wait for her coming out, my ScanGauge shows around 45 mpg for a day's driving. Luckily I get a two, sometimes three 80-mile trips every seven days.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 18, 2021, 07:36:07 AM
MPG is not too bad. Today, from yellow light on and 388 miles, it worked out to be 51.3 ("Fibometer" - 52.5).
This time last year, the calculated figure was 52.7 mpg. Now that the new all-weather tyres are getting the edges scrubbed off the fuel efficiency is improving. And let's not forget, that is still with sitting with the engine running for the few minutes I have to wait on my wife finishing work on the frosty days.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jackroosall on January 23, 2021, 11:08:18 PM
Honda Jazz Sport SE 2003.
43-47 winter use
45-49 summer use
mainly rural driving below 60.
Mileage 107000
Serviced at regular intervals.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 24, 2021, 12:15:09 PM
Welcome. Yes, keeping the speed below 60 makes a big difference. I seldom go any faster. I read somewhere that the i-DSi Jazz returns it's best mpg at 53 mph(?) so I try to keep around that speed. Max torque is just above 2,500 rpm so the is a good place to stay.

(https://i.imgur.com/fkSR1Gx.jpg?1)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on January 24, 2021, 01:01:55 PM
One thing I have noticed Jocko is that your fibometer readings are much closer to the actual mpg than mine and many others. Is this because of a smooth driving style do you think?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 24, 2021, 01:33:54 PM
It may be. I only reset it every top-up, so we are talking around 400 miles between resets.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 27, 2021, 11:49:10 AM
Peter. Just picked my wife up from her work. Car cold outside the garage. Temp 2°, 2.1 miles at an average speed of 19.7 mph. 38.4 mpg (ScanGauge figures for Current Trip). Short cold journeys, in town, certainly depress the fuel efficiency (and the driver).
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 29, 2021, 08:09:20 AM
I had a spell of "Range anxiety" this past 24 hours. I just left my mother-in-law's when my low fuel light came on and I knew I had 50 miles to go before I would fill up at my usual Morrisons. My ScanGauge E can be set to display the miles left in the tank and as it is pretty accurate at calculating the amount of fuel used between top-ups, and the achieved mpg, I trusted that the range remaining would be pretty accurate as well, but now I know how an EV driver feels as he watches his remaining range wind down.
As it was, it still showed 46 miles remaining when I topped up this morning (49.7 mpg, "Fibometer" 52.4, 8.5 gallons put into the tank). At £45.53 (£1.17.7/litre) it was the dearest top-up since I stopped using 99 RON and the first time since 6th July 2020 that a top-up broke the £40 barrier.

This next tankful I am not going to use any fuel-saving techniques so I'll see what I can get using that approach.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on January 29, 2021, 11:07:47 AM
It will be interesting to see what you do get. I think you manage to get in quite a few medium type trips. I pretty sure I'd be at around 50 mpg if, for example, I did my old work commute (34 miles return). This was on the M57 and M60 and, at the times I travelled, I rarely went about 60 mph.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on January 29, 2021, 06:03:24 PM
Yes, I make an 80-mile round trip, once, or as now, twice a week. Usually, I sit at around 55 mph. I also have two four mile trips every day, Monday to Friday, taking my wife to and from her work in town. Add to that a mile each way to and from Morrisons a couple of times a week and that's about it
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on February 09, 2021, 07:14:50 PM
This morning my fuel light came on, and with the weather we are having, I thought it better to top up.
As I said last time, this fill-up I have been driving the car with no effort to get good mph, just driving as anyone would and even sitting with the engine running to keep warm while I waited for my wife finishing work. The weather has been horrendous. Before the snow arrived this week, we have had minus temperatures, gale-force winds and heavy rain.
The "Fibometer" told me I had achieved 51.9 mpg, but I didn't believe it. I was right. I only got 51.3 mpg!
I couldn't believe it. That was better mpg than the last time I filled up, before changing my driving style
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on February 24, 2021, 10:13:25 AM
I thought I'd post about my experience of an ECU reset. It was triggered because I replaced the EGR valve. I'd been cleaning the old one every few months but it never stayed fixed.

Immediately after the change the engine was running abominably. Lumpy on tick over, hesitant and then the tick over dropped so low it kept on dying. Fortunately someone posted on here that it can take 2 or. 3 resets before the ECU gets it right. After two attempts I was confident enough to take the dog over to Ilkley moor, a run that usually gives good mpg. When I got there the dash was showing 61 odd mpg. I've never seen anything like that before. By the time I got home it was down, but still in the mid fifties.

My guess is the ECU had been masking something not right on the engine, sacrificing economy for smooth running. Possibly the PCV valve or a small leak in all that intake side pipework. Any suggestions for likely culprits gratefully received.

Given how dismally it was running in the default state it's amazing how well it usually runs.

Sadly I'm not equipped to tackle something like the PCV but hopefully I'll be able to set my brother on to it when lock down permits.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on February 25, 2021, 04:59:35 PM
I thought I'd just check that the rough running wasn't due to a coil or spark plug. When I took the plastic cover off one of the front coils was disconnected. I'll give it another reset and see if it's better. I don't think I had a senior moment (but would I?) so I suppose the plastic clip isn't locking any more.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jazzmeister on March 09, 2021, 12:31:53 PM
4.9L/100km OBC on a 1.5Vtec Mk1.

I've managed to get my economical driving technique right, finally after driving like an idiot and blaming the poor car.



(https://uploads.tapatalk-cdn.com/20210309/406b453b5778dffed5e23eaf8a4e02d3.jpg)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on March 09, 2021, 12:37:00 PM
Well done. My calculated average is 5.1. What is your calculated figure?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jazzmeister on March 10, 2021, 08:54:31 AM
Well done. My calculated average is 5.1. What is your calculated figure?
Yet to see that after my changed habits, end of the month when I fill up, I've just never managed anything like 4.9 on the OBC before and that was taken in urban driving conditions, I've only got close to that recently on the freeway, I was surprised to see that in town.

But your amazing average will not be in any danger, if I can get an average between 6-7L I'll be happy.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on March 16, 2021, 05:21:14 PM
Today I had a trip over to the Royal Infirmary Edinburgh with clothes and stuff for my mother-in-law, who is currently a patient there. When I joined the A92 dual carriageway at Kirkcaldy, I joined behind an empty HGV flatbed with one of those considerable cranes behind the cab, an ideal vehicle for drafting. I followed it along the A92, M90, M9 and M8, all the way to Hermiston Gait, keeping 3 to 5 seconds behind it, at speeds of between 50 – 55 mph. When we parted company, my ScanGauge E showed 58.5 mpg for the 28-mile trip. Without the help of the HGV, I would have expected 48 mpg, at best. Unfortunately, I spoiled my excellent work by driving for 5 miles, on the return journey, in 4th gear instead of 5th. The engine is so quiet, and with the fan on position four, trying to get some cool air into the car, it was an easy mistake.
I topped up the tank on my return, and this tank full returned 56.7 mpg. It looks like my all-weather tyres are not impacting my fuel consumption.
My average for my last ten tankfuls worked out at 51.3 mpg (Fuelly figure). That is from 10th December 2020. So throughout the winter, with all the rain and The Beast From the East 2, a total distance of 3,600 miles. Since the Lockdown started after Christmas, I have clocked up 3,000 miles, which I would rather I hadn’t.

(https://i.imgur.com/XAViB7t.jpg)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jackroosall on March 17, 2021, 04:03:35 PM
Average 42-45 mpg on short runs.
45-49mpg on longer runs.
These figures take into account display is usually up to 10% inaccurate.
The figures are based on trip meter mileage and full to empty tank.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on March 17, 2021, 05:21:58 PM
Just reflecting on Jocko's post above I think cruising at circa 60 mph on longer journeys is a huge influence on mpg. I have adopted an inside lane strategy like him in recent years with occasional bursts to overtake slower lorries.

I looked back at some mpg figures from UK holidays and I averaged 47 mph on a trip to Cornwall in a Mk2 Jazz. I was at 70 mph actual virtually the whole way (although there was a fair bit of wet weather and headwinds). I think you can tend to think that sitting at 70 mph on the motorway is an economical cruising speed - not in a small car and all cars will be affected by the extra wind resistance at high speeds.

My 55 mpg performance last September on a mini break to North Yorkshire is entirely down to rarely getting up to 70 mph. The inside lane is your friend when it comes to economy.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: John Ratsey on March 17, 2021, 05:37:07 PM
Just reflecting on Jocko's post above I think cruising at circa 60 mph on longer journeys is a huge influence on mpg. I have adopted an inside lane strategy like him in recent years with occasional bursts to overtake slower lorries.
Same here. I don't intentionally indulge in slip-streaming but I appreciate to the positive effect on fuel economy. The inside lane can often be a less stressful place to be provided that there's no lorry getting too close behind me (in which case it's time to do some overtaking).
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jazzmeister on March 17, 2021, 07:18:54 PM
Just reflecting on Jocko's post above I think cruising at circa 60 mph on longer journeys is a huge influence on mpg. I have adopted an inside lane strategy like him in recent years with occasional bursts to overtake slower lorries.
Same here. I don't intentionally indulge in slip-streaming but I appreciate to the positive effect on fuel economy. The inside lane can often be a less stressful place to be provided that there's no lorry getting too close behind me (in which case it's time to do some overtaking).
I've also cottoned on to the lower stress when dawdling along at 60mph or whatever the case is, much safer and far more relaxing.

I actually can't believe I used to be so manic on the road, you barely get there faster, especially in urban areas and your stress levels go through the roof.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on March 18, 2021, 06:55:46 AM
Agreed. Our kid had a difficult period commuting from here, near Bradford, to Sheffield. Some very crowded motorway but it demonstrated that trying to keep up to 70 cut only a few minutes from the journey and used a lot more fuel.

By the way the rough running I mentioned was because the new EGR was faulty. Autodoc has a Teutonic warranty procedure that takes weeks. Still hopefully I'll get my money back as it seems I didn't need the EGR anyway.

Meanwhile I put a revs display on the OBDII reader. I noticed my tick over was 750, after an oil change it's 650.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: billyausten on March 26, 2021, 06:48:48 PM
First full tank used since getting our sport. I'm very pleased to report that the car averaged a calculated 49.6mpg over 374 mixed miles. The car itself indicated 50.1 over the same distance. All in I can't complain with that.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on March 26, 2021, 07:05:36 PM
That's not too shabby at all. It will improve as you get used to the car and as the weather gets warmer.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: sparky Paul on March 27, 2021, 11:41:04 AM
I've also cottoned on to the lower stress when dawdling along at 60mph or whatever the case is, much safer and far more relaxing.

I actually can't believe I used to be so manic on the road, you barely get there faster, especially in urban areas and your stress levels go through the roof.

Me too. I used to zoom about all over, I was terrible for setting off too late and cutting it fine.

I now appreciate a more leisurely drive, and try not to worry about time. As they say, "better off late in this world than early in the next".
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: JimSh on March 27, 2021, 12:11:59 PM

I now appreciate a more leisurely drive, and try not to worry about time. As they say, "better off late in this world than early in the next".

Aye, we're all getting a bit older.
Pity that more people don't think the same way.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Scotty on April 06, 2021, 12:08:59 PM
About 47 mpg on everyday usage. I drove 50 miles the other day sticking to about 60mph and got 54mpg.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on April 06, 2021, 03:29:42 PM
About 47 mpg on everyday usage. I drove 50 miles the other day sticking to about 60mph and got 54mpg.
These are pretty good numbers. Are these calculated figures or from the "Fibometer" (dashboard display).?
Fuelly.com is a great place to store and calculate your fuel efficiency.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: E27006 on April 10, 2021, 01:24:52 PM
A week ago, my 2006 1.4Dsi covered 485 miles in a day driving at a typical 55 mph including long sections of the  M11 and A1M when the roads were traffic-free.  re-brimming the tank at 427 miles  calculated  consumption at  60.1 mpg, the fibometer (trip meter mpg) over-read by a couple of mpg compared to the tank rebrim method
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on April 10, 2021, 01:56:06 PM
Those are good figures - shows how keeping the speed below 70 pays dividends.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on April 10, 2021, 04:54:13 PM
Excellent numbers. I can manage that in the summer, but I never get more than 40 miles at a stint. 485 miles in a day is a long drive. What was it? 10 hours behind the wheel?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on April 17, 2021, 08:53:04 PM
For the first time in a while, the "Fibometer" is currently registering 60 mpg for this tankful. What a difference the warm, dry weather makes.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: DomnicZZ on April 20, 2021, 08:47:44 PM
My most recent fuel up was a pathetic 34.4 MPG (36.9 Fibo) . A far cry from the 50 I managed last summer. Although I’m barely driving, and do only short journeys thanks to WFH, I felt something was wrong , I read somewhere on here that it could be a sticking brake pad. And sure enough that was the culprit. Turns out a rear caliper was stuck. £300 later I have a new caliper and all 4 new discs and pads . (The front ones were previously warped causing vibration hence got all 4 changed). I’m still doing limited driving, but the MPG has risen to 42MPG after about 60 miles. Hopefully will return to 50s in summer.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on April 21, 2021, 11:05:41 AM
Under normal circumstances a sizeable dip in mpg triggers a search for a cause but at the moment that can be hidden. I am up to 80 miles a day now but it looks like not for much longer.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: E27006 on April 23, 2021, 07:57:48 PM
After two tankfulls of super unleaded (thanks to Sainsbury's money off fuel vouchers!) my mpg improved although going back to normal unleaded has had no effect. Therefore, it appears that whilst super unleaded hasn't improved mpg over normal 95RON unleaded, it perhaps 'cleans' the system out.

My trip computer is now reading at fill-up around 48/49mpg, often staying in the 50's for fair amount of miles.
For years I have always filled with the enhanced octane fuel at Tesco, avoiding the regular cheaper fuel on the same pump.
Last week I had to fill with "regular" at a BP station, caught in the middle of nowhere,  do you know the car ran better on the BP regular, gear changes ( manual; gearbox) were cleaner and more polished,  the engine being less "snappy" and revvy in respobse to  the accelerator pedal, and the car seemed to pull better on slight upward  inclines in top at 30 mph avoiding the need to change down from 5th to 4th.
Can anyone else support this finding?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on April 23, 2021, 08:31:37 PM
I found the same, even going from Morrisons 95 RON to 97 RON. I also found slightly improved mpg but not enough to make the change financially viable. Shell and BP fuels are just so prohibitively expensive I would only use them if stuck in the middle of nowhere.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on April 29, 2021, 02:48:57 PM
Had to refill my tank again this morning. That is 6 top-ups this month with a total of 38.9 gallons (177 litres).
This tankful returned 59.2 mpg and the last 10 top-ups, as calculated by Fuelly, works out at 53.9 mpg.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on April 30, 2021, 11:52:51 AM
Hope your need to do this high mileage ceases soon Jocko. We are talking a lot of money here.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on April 30, 2021, 06:04:23 PM
We hope so too.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on May 04, 2021, 04:52:31 PM
Had to add another tankful today. I am just glad I am getting 59.3 mpg at the moment. If I still had my Volvo S40, returning 29.8 mpg, things would be a lot more costly.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on May 08, 2021, 06:49:02 PM
Had to fill my tank again. This is ridiculous. Refilling the tank every four days!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on May 19, 2021, 11:53:11 AM
My average for the last 3 months is now 47 mpg (UK) pretty good for me. I have no idea what's changed.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on May 19, 2021, 04:33:26 PM
My average for the last 3 months is now 47 mpg (UK) pretty good for me. I have no idea what's changed.

Not strictly to do with this topic but I notice you use Fuelly. I do as well but it has stopped automatically updating my mpg on my profile page. I've tried deleting and then putting the link back in but to no avail.

Does yours still update your mpg on here automatically?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on May 19, 2021, 05:00:19 PM
Since Mum's death, our mileage has reduced to 300-400 per week. It will probably jump back up after the funeral, once we start working in the house, we should drop to about 10-15 miles a week once we are all settled. I'll miss the driving something terrible.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Westy36 on May 19, 2021, 05:23:51 PM
Since Mum's death, our mileage has reduced to 300-400 per week. It will probably jump back up after the funeral, once we start working in the house, we should drop to about 10-15 miles a week once we are all settled. I'll miss the driving something terrible.
Very sorry to hear of your sad loss Jocko. Thoughts are with you.

To get your mileage up, get back in the habit of going for a drive just for the sake of it. I do, at least once a week or so. Sometimes, in silence, sometimes enjoying an CD or the radio. Something I've done ever since I've had a licence, and don't plan on stopping anytime soon!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on May 19, 2021, 06:27:27 PM
To get your mileage up, get back in the habit of going for a drive just for the sake of it. I do, at least once a week or so. Sometimes, in silence, sometimes enjoying an CD or the radio. Something I've done ever since I've had a licence, and don't plan on stopping anytime soon!
Thanks. That is what I liked about the bike. I love going for a drive but feel it is an expensive waste going myself. If my wife wants to go with me then great, but she tends not to want to. She will retire when we make the move so perhaps she will feel more like going for a run. Maybe if I promise her a coffee or an ice cream she may go. Otherwise, I will just have to get another bike!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Westy36 on May 19, 2021, 07:08:59 PM
Thanks. That is what I liked about the bike. I love going for a drive but feel it is an expensive waste going myself. If my wife wants to go with me then great, but she tends not to want to. She will retire when we make the move so perhaps she will feel more like going for a run. Maybe if I promise her a coffee or an ice cream she may go. Otherwise, I will just have to get another bike!
Yeah, a bike is pure indulgence to be fair. I have a bunch of routes from the door, that are roughly 60 to 80 mile loops. Great biking roads.  8)

I do them in the Jazz sometimes. It's nice to have the radio on, or an album on my MP3 player and just go. Might be a couple of gallons of fuel gone, but hey, you can't take it with you and the Jazz is really econimical.

Mrs W and me have always enjoyed trips out in the car. Sometimes, we do just go for a drive together, just to go for a drive together. No purpose, take it in turns. Enjoy it while we can, because road pricing and EV range anxiety are on the horizon to take the fun out of it all.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on May 19, 2021, 07:33:00 PM
One evening I went out on the bike for a 60-mile run, and never got further from my garage than 5 miles. I was up and down every lane and farm road in the vicinity. Great fun. My wife was a biker chick but not with me. My bike was sold long before we met.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on May 20, 2021, 08:22:15 AM
My average for the last 3 months is now 47 mpg (UK) pretty good for me. I have no idea what's changed.

Not strictly to do with this topic but I notice you use Fuelly. I do as well but it has stopped automatically updating my mpg on my profile page. I've tried deleting and then putting the link back in but to no avail.

Does yours still update your mpg on here automatically?

Yes, it seems to be working.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on May 20, 2021, 10:24:53 AM
To get your mileage up, get back in the habit of going for a drive just for the sake of it. I do, at least once a week or so. Sometimes, in silence, sometimes enjoying an CD or the radio. Something I've done ever since I've had a licence, and don't plan on stopping anytime soon!
Thanks. That is what I liked about the bike. I love going for a drive but feel it is an expensive waste going myself. If my wife wants to go with me then great, but she tends not to want to. She will retire when we make the move so perhaps she will feel more like going for a run. Maybe if I promise her a coffee or an ice cream she may go. Otherwise, I will just have to get another bike!

Sorry for your loss Jocko. It's been a difficult time for you of late.

Just on driving, I still enjoy it as well- it's not just a utilitarian thing for me. I often go the long way round to the shops!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on May 26, 2021, 12:08:03 PM
Thanks.

My mpg is not quite up to scratch at the moment but I think it is down to the cold wet weather. Usually, I get good mileage in May. This morning. top up returned 57.8 mpg, which for the type of driving I am doing is not the best.
My average for the last 10 fill-ups is only 56.5 mpg but at least I have only had to fill the tank three times this month, which makes a pleasant change.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: 150234 on May 31, 2021, 12:48:59 AM
Had to refill my tank again this morning. That is 6 top-ups this month with a total of 38.9 gallons (177 litres).
This tankful returned 59.2 mpg and the last 10 top-ups, as calculated by Fuelly, works out at 53.9 mpg.
How the hell are you getting 59.2 mpg? I can get 49 mpg on the motorway if I go at around 55 - 60 mph, but get me on some A roads and I am down to about 35 mpg. At the peak of my adventures, I was filling up from light on to full twice a week and was doing that for around 4 months. I was going through petrol like it was water.

Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on May 31, 2021, 10:55:11 PM
I have a ScanGauge E fitted which shows me instantaneous mpg. I can see when it is in Deceleration Fuel Cut Off mode, which I make as much use of as I can. In DFCO the car uses no petrol. I also do a little freewheeling in Neutral when appropriate. I try to avoid using the brakes, depending instead on anticipation. I keep the tyre pressures up about 3 psi. Basically just mild hypermiling tricks. My best ever tank full was 69.9 mpg calculated.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on June 06, 2021, 07:12:58 PM
I got a very pleasant surprise today, when I refilled the tank. The Fibometer was showing 62.9 mpg, and I reckoned it was a mile out, but the calculated figure was 60.5 mpg. This came as a real surprise as I have been driving back from Danderhall every afternoon and I seem to spend as much time in crawling traffic as I do driving on the open road.
The Edinburgh City Bypass is a nightmare (Scotland's M25) and now the Queensferry Crossing is an aerial traffic jam, every trip.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on June 21, 2021, 08:24:23 PM
The fourth tankful this month and as expected the petrol was up again. 127.7p/litre at Morrisons. Luckily I am getting great mpg at the moment. This time it was 61.6 mpg (Fibometer 62.9).
For the last 10 fuel-ups, Fuelly reckons I have averaged 58.9 mpg.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Droneranger on June 21, 2021, 09:46:48 PM
My apologies.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest4871 on June 21, 2021, 10:55:32 PM
Each to their own. I know you are not setting out to be harsh.

Jocko has a special enjoyment in maximising his MPG. I enjoy him sharing his enthusiasm and reading about his results and techniques.

I would never have the patience he has to do what he does even if I understood how he does it. I do admire him for his achievements.

Different horses, different courses?

Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on June 22, 2021, 07:19:04 AM
I do not really mean to be harsh, but i do not care what the MPG of my cars is, I also do not care very much about the price of petrol.
The First Gen Jazz will go to 30mph in first gear, it will go to 55mph in second, and third will take it up to the legal limit.
I never did either, until getting the Jazz. Up until then I just put petrol in when I needed it and drove how I felt like it on the day.
Then I got the Jazz and I suddenly found I was getting almost twice the mpg of my Volvo which the Jazz replaced. At about the same time I read an article on Hypermiling and was given my ScanGauge E. This set me on a path to trying to maximise my mpg, purely as a game. I enjoy video games and this was a video game I could do in real life. Continually trying to beat my high score.
As for the price of petrol, it is what it is. So far this month I have filled the tank four times and I will have another tankful before July arrives. I have so far this month spent £157 on petrol. As an OAP this is more or less a quarter of my State Pension for June, so the increasing price does trouble me. It is not critical. I just wish it was cheaper.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on June 22, 2021, 10:58:38 AM
I monitor my mpg even though cost is not really any factor given the tiny annual mileage I do these days. I took delivery of this car on the 29th of January last year and, as of today, it's just past 3,000 miles (in nearly 18 months).

That's not the same for everybody though. Having to do high mileages then the price of petrol is definitely a factor. It's noticeable, too, that rising fuel prices have quite an impact on the inflation rate.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: 150234 on June 22, 2021, 07:54:20 PM
So I never look at my MPG but on the duel carriageway today I averaged around 46mpg at around 70mph. This was with 5 people in the car on a fairly hilly stretch of duel carriageway. Not to bad considering the age of the car (2003 1st gen Jazz), that it was heavily loaded and the fact that I love to overtake as many cars as possbile in a journey.

As a previous poster has said the mk1 jazz will do 30mph in 1st, 60mph in 2nd and 80 in 3rd and that's all anyone needs to know as far as fuel economy is concerned. It's always funny to get someone in the car who is the type of person that is afraid to rev their car above say 4k rpm as then theres me bouncing of the red line like it's a trampoline.

In the later part of last year I was going through petrol like it was water and wasn't paying attention to what I was spending. The girl I was seeing was giving me fuel money as well and once I added it up I was spending around 400 quid a month on fuel. Which looking back was worth it but it certainly put my 17 year old through it's paces. 
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on June 22, 2021, 09:56:23 PM
So I never look at my MPG but on the duel carriageway today I averaged around 46mpg at around 70mph. This was with 5 people in the car on a fairly hilly stretch of duel carriageway. Not to bad considering the age of the car (2003 1st gen Jazz), that it was heavily loaded and the fact that I love to overtake as many cars as possbile in a journey.

As a previous poster has said the mk1 jazz will do 30mph in 1st, 60mph in 2nd and 80 in 3rd and that's all anyone needs to know as far as fuel economy is concerned. It's always funny to get someone in the car who is the type of person that is afraid to rev their car above say 4k rpm as then theres me bouncing of the red line like it's a trampoline.

In the later part of last year I was going through petrol like it was water and wasn't paying attention to what I was spending. The girl I was seeing was giving me fuel money as well and once I added it up I was spending around 400 quid a month on fuel. Which looking back was worth it but it certainly put my 17 year old through it's paces.

No good revving MK1 DSI above about 4,500 rpm as it 'runs out of breath'  (  it is an 8 valve engine ).  The DSI engine does better when kept below those revs and is much more drivable at low revs than the VTEC MK2.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on June 22, 2021, 10:19:43 PM
Today we were flitting some furniture so once the van set off we had to, "My Old Man, said follow the van", and catch up the 10 minutes start they had. It was a 98% dual carriageway/motorway journey and I kept it on the limit, traffic allowing, all the way. According to my ScanGauge E (normally within 0.5 mpg of the calculated figure), I averaged 51 mpg for the 40-mile trip. And we never caught up with the van. We arrived first because they took a different route!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: 150234 on June 22, 2021, 11:13:30 PM
So I never look at my MPG but on the duel carriageway today I averaged around 46mpg at around 70mph. This was with 5 people in the car on a fairly hilly stretch of duel carriageway. Not to bad considering the age of the car (2003 1st gen Jazz), that it was heavily loaded and the fact that I love to overtake as many cars as possbile in a journey.

As a previous poster has said the mk1 jazz will do 30mph in 1st, 60mph in 2nd and 80 in 3rd and that's all anyone needs to know as far as fuel economy is concerned. It's always funny to get someone in the car who is the type of person that is afraid to rev their car above say 4k rpm as then theres me bouncing of the red line like it's a trampoline.

In the later part of last year I was going through petrol like it was water and wasn't paying attention to what I was spending. The girl I was seeing was giving me fuel money as well and once I added it up I was spending around 400 quid a month on fuel. Which looking back was worth it but it certainly put my 17 year old through it's paces.

No good revving MK1 DSI above about 4,500 rpm as it 'runs out of breath'  (  it is an 8 valve engine ).  The DSI engine does better when kept below those revs and is much more drivable at low revs than the VTEC MK2.
That's interesting. I always find that if you wind the car out to redline in 1st then change into 2nd you seem to hit a deadspot in the power for about 10mph. Almost like 2nd gear is too high in comparison to 1st. The engine in my Jazz doesn't seem to do anything until about 3,000 rpm and 30 mph in second (the point at which 1st runs out) is well below that hence the deadspot in the power delivery that I have. If it wasn't for that dead spot from 1st to 2nd it would actually be fairly rapid up to 60mph as you would stay in 2nd from 30 to 60mph.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: 150234 on June 22, 2021, 11:22:28 PM
So I never look at my MPG but on the duel carriageway today I averaged around 46mpg at around 70mph. This was with 5 people in the car on a fairly hilly stretch of duel carriageway. Not to bad considering the age of the car (2003 1st gen Jazz), that it was heavily loaded and the fact that I love to overtake as many cars as possbile in a journey.

As a previous poster has said the mk1 jazz will do 30mph in 1st, 60mph in 2nd and 80 in 3rd and that's all anyone needs to know as far as fuel economy is concerned. It's always funny to get someone in the car who is the type of person that is afraid to rev their car above say 4k rpm as then theres me bouncing of the red line like it's a trampoline.

In the later part of last year I was going through petrol like it was water and wasn't paying attention to what I was spending. The girl I was seeing was giving me fuel money as well and once I added it up I was spending around 400 quid a month on fuel. Which looking back was worth it but it certainly put my 17 year old through it's paces.

No good revving MK1 DSI above about 4,500 rpm as it 'runs out of breath'  (  it is an 8 valve engine ).  The DSI engine does better when kept below those revs and is much more drivable at low revs than the VTEC MK2.

As my Jazz has spent it's entire life before me pootling about, i like to drive the car in a spirited manner when outside of the 30mph limit. I have been driving the Civic type R for 17 years and treat my Jazz the same, I have found it to be quite capable if driven hard.
I have not experienced the engine running out of breath, even when driving up a steep bendy hill pretty much flat out.
What exactly do we mean by "run out of breath"? If you want to get away quick surely running up to redline in 3rd at 80mph is better than say changing gear into 4th way back at 4500rpm? Yes 4,500 rpm may be where the power is but surely being in a lower gear makes up for that in terms of the quickest way to get to 80?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on June 23, 2021, 08:38:16 AM
What exactly do we mean by "run out of breath"? If you want to get away quick surely running up to redline in 3rd at 80mph is better than say changing gear into 4th way back at 4500rpm? Yes 4,500 rpm may be where the power is but surely being in a lower gear makes up for that in terms of the quickest way to get to 80?

The difference between 'flexible' and 'peaky' engine  --  the MK1 DSI engine,  being 2 valves per cylinder and no ability to alter valve timing with revs is 'flexible' and in my experience much nicer to drive everyday than the 'peaky' VTEC MK2 Jazz,  which ( from experience ) feels pretty gutless below 2500 revs but has a higher specific power and because of the VTEC the power continues to build in proportion to revs.  The problem you have highlighted about large 'gap' between 1st and 2nd gear is more of a problem on the VTEC than the iDSI

https://mechanics.stackexchange.com/questions/7922/engine-power-specification-at-different-rpm
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: 150234 on June 23, 2021, 03:26:15 PM
What exactly do we mean by "run out of breath"? If you want to get away quick surely running up to redline in 3rd at 80mph is better than say changing gear into 4th way back at 4500rpm? Yes 4,500 rpm may be where the power is but surely being in a lower gear makes up for that in terms of the quickest way to get to 80?

The difference between 'flexible' and 'peaky' engine  --  the MK1 DSI engine,  being 2 valves per cylinder and no ability to alter valve timing with revs is 'flexible' and in my experience much nicer to drive everyday than the 'peaky' VTEC MK2 Jazz,  which ( from experience ) feels pretty gutless below 2500 revs but has a higher specific power and because of the VTEC the power continues to build in proportion to revs.  The problem you have highlighted about large 'gap' between 1st and 2nd gear is more of a problem on the VTEC than the iDSI

https://mechanics.stackexchange.com/questions/7922/engine-power-specification-at-different-rpm
This might be specific to my engine in my car or it maybe a more general thing but I find that, especially in the higher gears, the engine performs and responds better if you "feed" the throttle over 2 seconds or so than if you just mash it. Overtaking on the motorway is an example of this. If I sit at 80 and wish to overtake I will struggle to really get moving if I mash it but if I take a few seconds to feed it it's almost like I am giving the engine chance to react to my input. Still only 84hp mind you so it's never going to be quick, but it's certainly capable of being nippy if you drive it hard. The car is also very light which helps althought it is a bit like driving a kite when it's windy.

Is thing something you have noticed on the VTEC engine in the mk2 Jazz?

Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: RichardA on June 27, 2021, 11:22:49 AM
Posts regarding 1930 Morris Minor chassis moved to here:
https://clubjazz.org/forum/index.php?topic=13306.0

All other off-topic posts removed.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on July 02, 2021, 08:03:59 PM
Today I had to top-up the tank again and I was not expecting a great number. We have a builder doing work at the new house and when he finishes, and we set off for home, we are right in the evening rush hour. However, for the past 430 miles and 7 and a smidge gallon, I have averaged 60.0 mpg. I can only put it down to the lovely warm dry weather.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on July 03, 2021, 12:42:01 PM
Great figures as always - MK4 economy from a MK1.

PS

Wonder if you could get three figures mpg out of a MK4? :)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: nowster on July 03, 2021, 01:33:40 PM
Wonder if you could get three figures mpg out of a MK4? :)

Very possibly. I've had it report 85mpg on a 5 mile trip that was mostly 30-40mph.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on July 03, 2021, 02:15:28 PM
Figures for a 5 mile trip are meaningless. First off, the display is optimistic and the terrain plays a huge part. I have recorded 108 mpg for a 6 mile trip using my Scangauge. Only real test is top up to top up and even then several are needed for an accurate figure.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Bazzzer on July 03, 2021, 04:27:58 PM
I actually had my Mk3 showing 199.9 mpg the other day.  Perhaps that's as high as it goes.

I'd started from a car park at approx 500' up and, after initial acceleration, trundled down to a crossroads 1.4miles away at 150'.  There was a car in front, so I couldn't have gone much faster if I'd tried.

As I approached the bottom, I saw 172.8, 187.2 and finally 199.9 mpg.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: nowster on July 03, 2021, 09:35:48 PM
Figures for a 5 mile trip are meaningless. First off, the display is optimistic and the terrain plays a huge part. I have recorded 108 mpg for a 6 mile trip using my Scangauge. Only real test is top up to top up and even then several are needed for an accurate figure.

Very true. I'm recording my fills in an app on my phone. I've only filled up twice so far, so only have one measurement to go by. (The initial fill from the dealership doesn't count.)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on July 03, 2021, 10:15:52 PM
I use Fuelly.com and here is my dashboard image with my last 10 top-ups.

(https://i.imgur.com/fTYRa8t.jpg)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: KJazz on July 04, 2021, 05:36:23 PM
54 last time I looked on my 2003 Jazz, mixed town and motorway driving. Great machine.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: DomnicZZ on July 05, 2021, 01:44:21 PM
Got my best tank to date. 57.7 (60.3 Fibo) that’s about 450 miles for 35 litres, which I found to be quite good for a 1.4 CVT auto.

The warm weather and longer trips is what contributed to it. Fuelly is certainly a very handy way to keep track. I avoid going above 60 MPH and manually switch off at long red signals.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on July 05, 2021, 03:57:04 PM
I avoid going above 60 MPH and manually switch off at long red signals.
That is certainly the way to do it. And try and use anticipation instead of the brakes!
I have a ScanGauge E fitted to my OBD2 port and it is very helpful.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: 150234 on July 05, 2021, 04:27:31 PM
Interestingly, I also had slightly longer journey to make yesterday. However, it's safe to say I didn't do so well in terms of fuel economy. I average 39.2mpg over 101 miles of duel carriageway driving.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on July 07, 2021, 08:55:07 AM
Here's my, much more average, summary from Fuelly.

Ignore the 61.7 mpg best figure. It's because I used a pump that must have filled the tank to the brim, it was over 100 miles before the needle moved off the end stop.

So although tank to tank gives an accurate long term figure the indicator on the dash is useful for comparisons and showing short term changes. Just this week I saw my figures for familiar journeys were dropping and I had a look at the air filter. Sure enough it needed changing.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on July 07, 2021, 10:42:03 AM
Here's my, much more average, summary from Fuelly.

Ignore the 61.7 mpg best figure. It's because I used a pump that must have filled the tank to the brim, it was over 100 miles before the needle moved off the end stop.

So although tank to tank gives an accurate long term figure the indicator on the dash is useful for comparisons and showing short term changes. Just this week I saw my figures for familiar journeys were dropping and I had a look at the air filter. Sure enough it needed changing.

I agree with what you say about the onboard computer - they do highlight short term changes and the indicator that shows mpg in real time is a useful tool for seeing what different throttle inputs do (I rarely use it myself however).

Over time my onboard computer is around 9% out (optimistic). Given the amount of short trips I make it's always somewhere in the 40s so if you knock off 4 mpg it gives me a figure that is as close to reality as makes no difference.

Still use Fuelly though.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on July 08, 2021, 06:58:59 PM
Today I topped up my tank for the second time this month and lo and behold, another penny on a litre. My low fuel light came on less than a mile from the filling station. The tank took 35.11 litres, the trip meter showed 492.6 miles since the last top-up, the fibometer said 65.8 mpg and Fuellly calculated it out at 63.7 mpg. You have got to love the summer weather, wet as it has been.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: E27006 on July 08, 2021, 10:31:25 PM
Those of us complaining about unfair taxes on fuel,  perhaps we should stop driving cars and buy a business jet instead.
The EU is going to make business jets exempt from a carbon fuel tax,  that should please all those rock stars en route to a gig  and executives flying  to a G7 conference.

The European Commission’s planned carbon tax on jet fuel, which will be presented for legislation on July 14, will carry exemptions for private jets and cargo flights on the grounds that such journeys “aid to the conduct” of business, it was announced today. Apparently multi-millionaire celebrities jetting around the continent to visit their second homes is now classified as “business travel"
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: 150234 on July 08, 2021, 11:42:48 PM
I had a look at the air filter. Sure enough it needed changing.
Does it make that much differance? If it does then I might check mine because I have never done it and if it increases fuel economy then I assume that it would also work the other way and increase power output as well?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on July 09, 2021, 10:10:57 AM
It makes about 4 mpg difference on my car. As our cars age I suppose they vary, otherwise why would Jocko get such spectacular mpg. There was a very well informed discussion of it on here a year or so ago where someone made the case that with all the sensor data going back to the EMU it should be able to adjust for the reduced flow from an air filter and make no difference. But in practise for me it does. No noticeable change in power though.

I think the only way to find out is to try a new filter (or clean the existing one). It's an easy and cheap job.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on July 09, 2021, 10:18:01 AM
It makes about 4 mpg difference on my car. As our cars age I suppose they vary, otherwise why would Jocko get such spectacular mpg. There was a very well informed discussion of it on here a year or so ago where someone made the case that with all the sensor data going back to the EMU it should be able to adjust for the reduced flow from an air filter and make no difference. But in practise for me it does. No noticeable change in power though.

I think the only way to find out is to try a new filter (or clean the existing one). It's an easy and cheap job.

If less air flowing then oxygen sensors in exhaust will instruct ECU to reduce amount of fuel being squirted in, less fuel = less power.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: guest4871 on July 09, 2021, 10:33:32 AM
Even different air filters have an effect. I changed from a new Bosch to a new Fram. Noticeably better performance and better MPG.

Don't know why - but I am not complaining!

Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on July 09, 2021, 12:39:12 PM
I change my air filter every year. I have used cheap ones and dear ones and have never noticed any difference between makes or between the old one and the new one. Neither in performance or in mpg.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: 150234 on July 09, 2021, 06:55:18 PM
It makes about 4 mpg difference on my car. As our cars age I suppose they vary, otherwise why would Jocko get such spectacular mpg. There was a very well informed discussion of it on here a year or so ago where someone made the case that with all the sensor data going back to the EMU it should be able to adjust for the reduced flow from an air filter and make no difference. But in practise for me it does. No noticeable change in power though.

I think the only way to find out is to try a new filter (or clean the existing one). It's an easy and cheap job.
I have had my car 15 months now and I haven’t checked or changed the air filter since I had it and I doubt that the mechanic has either. It will be interesting to see how it’s looking. Pretty dirty I would expect.

Can you clean them or do you just by another one?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: 150234 on July 09, 2021, 06:56:57 PM
It makes about 4 mpg difference on my car. As our cars age I suppose they vary, otherwise why would Jocko get such spectacular mpg. There was a very well informed discussion of it on here a year or so ago where someone made the case that with all the sensor data going back to the EMU it should be able to adjust for the reduced flow from an air filter and make no difference. But in practise for me it does. No noticeable change in power though.

I think the only way to find out is to try a new filter (or clean the existing one). It's an easy and cheap job.

If less air flowing then oxygen sensors in exhaust will instruct ECU to reduce amount of fuel being squirted in, less fuel = less power.
Less power meaning that you’re more likely to squeeze the peddle a bit more and therefore use more fuel in the long run.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on July 09, 2021, 07:32:13 PM
Can you clean them or do you just by another one?
Just buy another.


https://www.ebay.co.uk/itm/273374545034?fits=Car+Make%3AHonda%7CCars+Year%3A2003%7CModel%3AJazz&_trkparms=ispr%3D1&hash=item3fa664848a:g:I-wAAOSwZtpg5vIb&amdata=enc%3AAQAGAAACkPYe5NmHp%252B2JMhMi7yxGiTJkPrKr5t53CooMSQt2orsSlHY%252FYTip4QFVjNQrCEJt6rGfu58BVUCC1ZmPW4i%252B627yrst8xLCheU%252B1uOGGM7yMdn2RszZgK9OEHmApLC1sHirKIHhO55iKR4o%252FWLk58tQndZn8gzPg%252FfpASKuUhvMvZSqz21IjhMzriGkahLkz6XLHXvProuAMOCIvoWeI018AoxYIxEVoswCbZ02ykLYWL51T%252F%252F26wwl7%252Bmv1%252FzxuhBCO%252F4jFhkl2oHIN29fzIserkeEit84vyqMFMdHHKmGQt%252BNz%252FclLRyqzJe5Bnm3FUsTxTMQxA%252B0flxsKOywzB8Qz%252BZ1gAL23dn%252Bpmh2Dw9ZdV%252B9vsX%252BXfhOp1Hx9I5BTE7OI4TWb1oQmuqSy0KqMgfZP00brRpI9Nf5PInM5FWOJUamCthJ7iYWbmgDYEeinYwqo0FZ6RbvuqJmj27Z4OGAndQq%252F1rjjfBNVJpS0g9anbBfnY%252FcbXvrZGUKDZhnkyqIeggYg4oEjpibxMaZ0xEciMJ7ph%252BlaGCTLPTUdE7E2MrGHVsOCtEEnBGN%252B7uqgpWV8uTae4lo5Lm7KVOiHqBWPSCDqfaACGJRX4w7Sr5YBCKKOh%252F9S0qFF4KzZCMWNIA9hDU5Te9xd8ck9XJd9cC5fIaPy5HcpdnnOs0cF2vAlI0U7h6Pj2qBHO0e1W%252FJT%252FQ%252FgI8pBO9aslm20DMSbopk3TBcy8fv5XNCZiGZaUlTVJKTLDTNYmjLnYkBBVq6m1rWGsOjH34VUDuXOO4Ce%252Fwm6BbmtGEW53cBMaC5ZKfV5yZw3k1IrSxhoaFCfMGBwtrhp97FxZX0EkROHcQPKrcX6x%252F490ky%252FpLvRP0f8S2S0%7Campid%3APL_CLK%7Cclp%3A2334524 (https://www.ebay.co.uk/itm/273374545034?fits=Car+Make%3AHonda%7CCars+Year%3A2003%7CModel%3AJazz&_trkparms=ispr%3D1&hash=item3fa664848a:g:I-wAAOSwZtpg5vIb&amdata=enc%3AAQAGAAACkPYe5NmHp%252B2JMhMi7yxGiTJkPrKr5t53CooMSQt2orsSlHY%252FYTip4QFVjNQrCEJt6rGfu58BVUCC1ZmPW4i%252B627yrst8xLCheU%252B1uOGGM7yMdn2RszZgK9OEHmApLC1sHirKIHhO55iKR4o%252FWLk58tQndZn8gzPg%252FfpASKuUhvMvZSqz21IjhMzriGkahLkz6XLHXvProuAMOCIvoWeI018AoxYIxEVoswCbZ02ykLYWL51T%252F%252F26wwl7%252Bmv1%252FzxuhBCO%252F4jFhkl2oHIN29fzIserkeEit84vyqMFMdHHKmGQt%252BNz%252FclLRyqzJe5Bnm3FUsTxTMQxA%252B0flxsKOywzB8Qz%252BZ1gAL23dn%252Bpmh2Dw9ZdV%252B9vsX%252BXfhOp1Hx9I5BTE7OI4TWb1oQmuqSy0KqMgfZP00brRpI9Nf5PInM5FWOJUamCthJ7iYWbmgDYEeinYwqo0FZ6RbvuqJmj27Z4OGAndQq%252F1rjjfBNVJpS0g9anbBfnY%252FcbXvrZGUKDZhnkyqIeggYg4oEjpibxMaZ0xEciMJ7ph%252BlaGCTLPTUdE7E2MrGHVsOCtEEnBGN%252B7uqgpWV8uTae4lo5Lm7KVOiHqBWPSCDqfaACGJRX4w7Sr5YBCKKOh%252F9S0qFF4KzZCMWNIA9hDU5Te9xd8ck9XJd9cC5fIaPy5HcpdnnOs0cF2vAlI0U7h6Pj2qBHO0e1W%252FJT%252FQ%252FgI8pBO9aslm20DMSbopk3TBcy8fv5XNCZiGZaUlTVJKTLDTNYmjLnYkBBVq6m1rWGsOjH34VUDuXOO4Ce%252Fwm6BbmtGEW53cBMaC5ZKfV5yZw3k1IrSxhoaFCfMGBwtrhp97FxZX0EkROHcQPKrcX6x%252F490ky%252FpLvRP0f8S2S0%7Campid%3APL_CLK%7Cclp%3A2334524)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: 150234 on July 09, 2021, 10:33:21 PM
Mission failed:

I couldn't get the screws undone. They were either really tight or have rusted solid. Either way, mission failed.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on July 10, 2021, 07:53:49 AM
Mission failed:

I couldn't get the screws undone. They were either really tight or have rusted solid. Either way, mission failed.

If the screws are that rusted the air filter may never have been replaced.... looks like from MY 2005 screws replaced by clips. This guy mentions a dremel

https://clubjazz.org/forum/index.php?topic=12586.msg89752#msg89752
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: 150234 on July 10, 2021, 06:39:08 PM
Mission failed:

I couldn't get the screws undone. They were either really tight or have rusted solid. Either way, mission failed.

If the screws are that rusted the air filter may never have been replaced.... looks like from MY 2005 screws replaced by clips. This guy mentions a dremel

https://clubjazz.org/forum/index.php?topic=12586.msg89752#msg89752
They are pretty solid. I did manage to break two free and get them spinning which I have left loose ish to make sure I can get them again when I get around to breaking the rest free.

I will try filling the little plastic dips that the screws are in with WD40, letting that soak in for an hour or so and then try again. If I can get them free that would be good because as you say, the air filter is likely the original and unopened.

Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on July 14, 2021, 06:00:01 PM
Filled my tank again this morning and once again there was another penny on a litre. 411 miles this time and 63.2 mpg (calculated). Fibometer reckoned 63.4 so pretty well spot on.
Delighted to say that for the first time ever Fuelly has me at 60.0 mpg for the last 10 top-ups.

(https://i.imgur.com/M38lEYL.jpg)

Mind you, that is the first time I have had 10 top-ups all in summer. 10 in 7 weeks, to be precise.

That is me now put 1001 gallons in the tank, since buying the Jazz, 5 years ago.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: fashionphotography on August 02, 2021, 04:28:53 PM
well im not sure how accurate the dash info is but on my 1.4 2007 jazz its showing 31mpg  ? the engine is running sweet and has been serviced. although i did have a flat battery when i picked it up .. all ok now but could the ECU need to be reset . im sure 31mpg isnt right.. my old Subaru Forester 2.0l auto was doing 38 plus .
plus i may add im driving it like an old man lol.. no hi revving just smooth changes etc
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 02, 2021, 06:14:24 PM
I hate to tell you this but the dash display is usually optimistic! Calculate your figures from one top-up to the next.
My display said 61.4 mpg when I topped up today but my Fuelly/Spritmonitor figure was only 55.7 mpg.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: fashionphotography on August 02, 2021, 06:52:51 PM
at least its reading a rough estimated economy a lot more than mine.. . when i got the car the reserve light just came on.. we put £20 in the tank which brought it up to half way.. the trip  states we have done 40 miles and its just over a quarter of a tank at the moment
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 02, 2021, 07:37:49 PM
So what mpg is it showing for the 40 miles, or is that the mpg figure?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: fashionphotography on August 02, 2021, 07:48:18 PM
ive only just tried the mpg readout today it fluctuated between 31.3 to 31.8 mpg .. just urban driving but little traffic
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 02, 2021, 08:39:12 PM
I normally rest the trip every time I fill-up the tank then leave it displaying mpg until the next top-up. Then when I refill the tank I can compare the display figure with the calculated figure.
I upload my numbers to Fuelly
https://www.fuelly.com (https://www.fuelly.com)
and SpritMonitor.
https://www.spritmonitor.de/en/ (https://www.spritmonitor.de/en/)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: fashionphotography on August 03, 2021, 07:14:11 AM
I normally rest the trip every time I fill-up the tank then leave it displaying mpg until the next top-up. Then when I refill the tank I can compare the display figure with the calculated figure.
I upload my numbers to Fuelly
https://www.fuelly.com (https://www.fuelly.com)



yes i usually work out economy like that anyway. also not knowing the design of the tank . taking into account most tanks only hold about two thirds of the upper section due to the shape. i was just taken back as most people on here say there readouts are higher than the true figures. im just hoping mines much lower for some reason lol
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 03, 2021, 04:43:40 PM
My last top-up was rather disappointing and now I know why. I checked my tyre pressures a week ago and they were all fine, but today I thought a rear tyre looked a bit soft. I checked it and it was down to 11 psi. Now recently I have been spraying my tyre valves with leak detector solution, having ruined a tyre because of a leaking valve, but the spray is at my garage in Kirkcaldy and I checked the tyres in my drive at Danderhall (I wanted to check out my birthday present, a cordless compressor). Checked the valve today and it was fine, so I will check on the pressure to make sure I don't have a slow puncture elsewhere (I didn't see anything).
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: fashionphotography on August 11, 2021, 03:07:31 PM
further to my £20 top up to halway from the low warning light coming on.. its works out roughly ive done 100 miles on that £20.. is that good or ?????
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: JimSh on August 11, 2021, 04:41:12 PM
further to my £20 top up to halway from the low warning light coming on.. its works out roughly ive done 100 miles on that £20.. is that good or ?????
You should really use a more reliable fixed point than either the point where the warning light comes on or the halfway point on the gauge but if you reckon you've done 100 miles on £20 divide the £20 by the price you paid per litre, convert to gallons (1gallon = 4.55 litres) then divide the 100 miles to find mpg.

Eg £20/£1.33 =15.4l=3.4gallons
     100mls/3.4gallons = 29.4mpg
      30mpg not good  :(

Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: fashionphotography on August 11, 2021, 05:27:25 PM
hence thats why my guage is showing only 32 mpg on the dash .. which is way under what everyone elses is showing .. yet shes running sweet as a nut.. although i must admit ive only done urban driving taking the wife to work and back .. ive had the car 2 weeks now . 63000 miles from new with full history
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on August 11, 2021, 08:43:52 PM
hence thats why my guage is showing only 32 mpg on the dash .. which is way under what everyone elses is showing .. yet shes running sweet as a nut.. although i must admit ive only done urban driving taking the wife to work and back .. ive had the car 2 weeks now . 63000 miles from new with full history

I guess, as others have suggested, a brim to brim mpg check might give a truer picture. For what it's worth, though, the mpg on my early 2020 Mk3 is not good, it's even below the combined WLTP figure but my average speed is about 16 mph and that's because most of my trips are around 3 miles return. Your low figures might be down to the pattern of use.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: fashionphotography on August 13, 2021, 08:45:29 AM
just filled mine up last night so il check that against the trip .. although the mpg meter thismorning said 28mpg from cold rose to 35 mpg by the time i got back when it was warm.. just wondering what other owners mpg meter reads from cold and starting off in the mornings ?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 13, 2021, 08:58:29 AM
I only reset my trip every top-up, not every day (Mk1 only has the one). However, my ScanGauge auto resets every trip and from a cold start will give similar numbers to those you are seeing. It depends on the route and driving style.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 14, 2021, 11:03:05 PM
@fashionphotography. How much use do you make of 5th gear? I use 5th most of the time. On a level road, I am into 5th by 25 mph. The only time I use 4th is changing up on a steepish hill. Normally 1,2,3,5.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 14, 2021, 11:05:28 PM
Filled up my tank yesterday after 514.4 miles. The 39-litre tank took 38 litres. Fibometer said 61.6 mpg and Fuelly's calculation said 61.6 mpg.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: fashionphotography on August 15, 2021, 09:06:03 AM
@fashionphotography. How much use do you make of 5th gear? I use 5th most of the time. On a level road, I am into 5th by 25 mph. The only time I use 4th is changing up on a steepish hill. Normally 1,2,3,5.

well tbh i havent had much chance to take her on a descent run yet .. just local urban runs. but  i do always drive like its sunday lol ..  keeping the revs low and making the most of all the gears. im hoping when we go up north next friday on the motorway it should read more than its reading now.. im not sure what other members  guages read when travelling just around town .
i see everyones posting the max the fibometer is showing but would live to hear what they are showing on short trips urban driving
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 15, 2021, 12:22:27 PM
I use 5th all round town, even in heavy traffic. If my speed is about 20 mph,in it goes.
The other evening I got stuck in traffic. 4 miles in half an hour (8 mph average) but still got 38 mpg for the trip.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Masiedog on August 15, 2021, 08:42:51 PM
1.4 SE 300 miles on a tank is that poor or to be expected?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 15, 2021, 10:05:11 PM
It depends on how low you let the fuel drop before you filled up. I normally wait until the low fuel warning light comes on.
The best way to check it is to use something like Fuelly.com or SpritMonitor.com, where you enter your mileage and litres each top up and it calculates your miles per gallon. You can do it with a calculator as long as you record the mileage at each top-up.
(Current mileage - previous mileage) /(litres/4.55)=mpg.

I just filled my tank after 514 miles between top-ups.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: 150234 on August 16, 2021, 12:06:49 AM
1.4 SE 300 miles on a tank is that poor or to be expected?
It's better than what I get so it can't be too bad.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Masiedog on August 16, 2021, 01:21:53 PM
We own a 2005 1.4 se Jazz with careful driving we only got 300 miles on a tankful ! Which to our dodgy calculation is around 30 mpg , but the engine management light is always lit  :o
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: 150234 on August 16, 2021, 04:56:01 PM
We own a 2005 1.4 se Jazz with careful driving we only got 300 miles on a tankful ! Which to our dodgy calculation is around 30 mpg , but the engine management light is always lit  :o
I assume you're brimming the tank when you fill up right? Also, when are you filling up? Yellow light or before?

Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: fashionphotography on August 17, 2021, 08:29:38 AM
We own a 2005 1.4 se Jazz with careful driving we only got 300 miles on a tankful ! Which to our dodgy calculation is around 30 mpg , but the engine management light is always lit  :o
I assume you're brimming the tank when you fill up right? Also, when are you filling up? Yellow light or before?


think as they say its on all the time as its the engine fault light.. most likely the cause of the poor economy.. my gauge is showing 35mpg around town now. although my engines running faultless
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: culzean on August 17, 2021, 09:02:13 AM
We own a 2005 1.4 se Jazz with careful driving we only got 300 miles on a tankful ! Which to our dodgy calculation is around 30 mpg , but the engine management light is always lit  :o
I assume you're brimming the tank when you fill up right? Also, when are you filling up? Yellow light or before?


think as they say its on all the time as its the engine fault light.. most likely the cause of the poor economy.. my gauge is showing 35mpg around town now. although my engines running faultless

Fault light could be dodgy oxygen sensor and fuel injection gone into 'open loop' mode ( default uncontrolled mode which gives a constant rich mixture )....
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 17, 2021, 09:56:32 AM
The fault could have been and gone. The light stays on until you reset it. Buy a cheap OBD2 code reader from Amazon or the like. About £15. That will tell you what the problem is/was and let you reset it.
Yesterday, I watched my ScanGauge, and even with a warm engine it took about 5 miles to average better than 40 mpg, from a journey start.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 19, 2021, 07:36:14 PM
Topped up the tank today after 497 miles and 60.1 mpg. That is six out of the last ten top-ups 60+ mpg (and two were 59 something).
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: knobbly on August 21, 2021, 05:00:38 AM
This year I have had two long journeys with impressive MPG in my 2002 1.4.  The latest is 72.5 over 180 miles using the dash indicator.  When later filling up this worked out at 59.3 over the full tank(66.3 indicated) which then included some city work too. 
Like Jocko I pull the highest gear I can, 38psi and stay within speed limits as I have motorbikes for my need for fun and speed! The engine has a very old fashioned torque curve like an old A series Austin Morris unit, but much smoother.  More specifically it is suited to sensible driving and not chasing 0-60 times or theoretical top speeds.
I do not know when the car was last serviced, bu the oil has only just become black as opposed to discoloured and the air filter was blown out with an airline, but not changed. It has only done 31k miles so is very low and feels to be in fine fettle being so smooth and absolutely silent at tickover. It really has proved to be a fine car over the 7 months and 6k that I have owned it, with no attention required beyond petrol and windscreen wash. I will change the oil for the winter and apply some Dinitrol as a reward, but that wil be it untill I do a full service next summer.
Long may this peformance continue.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 25, 2021, 08:51:33 PM
Well, I think I will have to give up my crown for a non-hybrid Jazz mpg. Today I filled up for the last time before the car becomes a city shopper. I have two more trips back to the old house then it is into the drive, charger connected up and one 7 mile round trip to Asda every couple of weeks. Just when I got my Blue Badge too.
I have always enjoyed driving (hence the reason I have had jobs driving buses and coaches as well as a couple of jobs as a van delivery driver) and will really miss being out on the road. Since the start of the year, I have done 13,000 miles (not bad for a 15-year-old Jazz), and, though I won't miss such a large number of miles I will miss it.
And today's figure. 62.8 mpg for a 488-mile tankful.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: sparky Paul on August 25, 2021, 10:29:30 PM
Well, I think I will have to give up my crown for a non-hybrid Jazz mpg. Today I filled up for the last time before the car becomes a city shopper. I have two more trips back to the old house then it is into the drive, charger connected up and one 7 mile round trip to Asda every couple of weeks.

I'm sure you'll find some nice days out in the summer, at least bump it back up then.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on August 26, 2021, 10:40:58 AM
The fault could have been and gone. The light stays on until you reset it. Buy a cheap OBD2 code reader from Amazon or the like. About £15. That will tell you what the problem is/was and let you reset it.
Yesterday, I watched my ScanGauge, and even with a warm engine it took about 5 miles to average better than 40 mpg, from a journey start.

That's really interesting and is further confirmation as to why my mpg is so poor. in fact poor might be the wrong word, any car might struggle to attain decent figures given my driving profile.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: fashionphotography on August 26, 2021, 04:27:09 PM
sticky mpg guage?????
only had my jazz about 3 weeks now. i was concerned at first as the first 2 weeks driving was just town short trips and the guage was showing average 32mpg then last weekend had a long 500 mile round trip up north.. after filling her tank up the .. the first motorway miles crept up to the max of 56mpg. great .. only thing is now the short town drives its  showing 54mpg all the time lol ?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on August 26, 2021, 04:47:18 PM
It will. Unless you reset the trip it will slowly drop as it shows the average, not instantaneous.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: JimSh on August 26, 2021, 04:55:07 PM
It's showing the average mpg.
First few weeks -short journeys few miles/few gallons - low mpg. Showing 32mpg
Long journey. Car warmed up good mpg.  Showing 56mpg
Back home short journeys. average mpg = total distance/ total  gallons
                                                          = (few miles +500mls + few miles) / total gallons
                                                          = mileage very close to what you were getting on long run Showing 54mpg.

Given more short runs it will slowly decrease.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: KJazz on September 22, 2021, 12:12:48 PM
55mpg town, 60mpg motorway at a steady 60mph. I put lots of miles on in the summer and have it serviced regularly.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: peteo48 on September 22, 2021, 12:17:53 PM
55 mpg round the the town is seriously impressive. I struggle to get over 40 mpg on short town runs.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: 150234 on September 22, 2021, 12:34:24 PM
55mpg town, 60mpg motorway at a steady 60mph. I put lots of miles on in the summer and have it serviced regularly.
How? How are you getting 60mpg at 60mph? I could never dream, I might get 45mpg if I really try.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: jazzyblue on October 09, 2021, 11:20:03 AM
I get around 45mpg around town, 55-60mpg on long runs.
I keep the Jazz for its fuel economy, and I generally like this car a lot :)
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: KJazz on October 24, 2021, 03:39:27 PM
Earlier in the summer I did a lot of motorway driving and got 60mpg keeping the speed between 60-65. Town driving of 54mpg.

Suddenly my 2003 Jazz is only getting 46 mpg town driving; I'm not on the motorway to compare.

What's up? Faulty sensor? It is a high mileage engine.   
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: nowster on October 24, 2021, 03:46:17 PM
Earlier in the summer I did a lot of motorway driving and got 60mpg keeping the speed between 60-65. Town driving of 54mpg.

Suddenly my 2003 Jazz is only getting 46 mpg town driving; I'm not on the motorway to compare.

What's up? Faulty sensor? It is a high mileage engine.

WINTER IS CØMING!  ;D
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: springswood on October 25, 2021, 07:42:40 AM
I've not noticed any great winter summer effect, possibly 1 or 2 mpg in my (current) average of around 45mpg.

I've always suspected the kind of mpg Jocko gets and KJazz was getting is the potential of the car but that most of us, with age, have had some deterioration. Like KJazz I think it's probably a sensor/throttle body/emissions control thing. But I've always found it too daunting to take it all apart to clean up/replace bits.

Of course the other contender for a sudden, significant change in mpg is a sticky brake calliper.

When you say high mileage, how much?
MODIFY I saw your other post, 170k+
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: petermac63 on November 09, 2021, 09:31:55 AM
My 1.4 sport (06) is getting a reasonable 50 mpg. Not bad considering it will very shortly pass 150,000 miles!
I am worried it may fail on emissions at its next m.o.t. though.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: 150234 on November 09, 2021, 04:51:00 PM
My 1.4 sport (06) is getting a reasonable 50 mpg. Not bad considering it will very shortly pass 150,000 miles!
I am worried it may fail on emissions at its next m.o.t. though.
Get a mate to get it through.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: 150234 on December 12, 2021, 02:01:36 AM
I've not noticed any great winter summer effect, possibly 1 or 2 mpg in my (current) average of around 45mpg.

I've always suspected the kind of mpg Jocko gets and KJazz was getting is the potential of the car but that most of us, with age, have had some deterioration. Like KJazz I think it's probably a sensor/throttle body/emissions control thing. But I've always found it too daunting to take it all apart to clean up/replace bits.

Of course the other contender for a sudden, significant change in mpg is a sticky brake calliper.

When you say high mileage, how much?
MODIFY I saw your other post, 170k+
I have this issue, my engine warning light has been on for emissions so that probably doesn't help.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on December 15, 2021, 06:45:45 PM
I topped up my tank today and recorded 44.6 mpg, my worst ever figures. Unfortunately, this is going to be the norm from now on with only short trips in and around Edinburgh. The good news is, instead of topping the tank up two or three times a week, this is my first petrol purchase in almost three months.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: 150234 on December 17, 2021, 01:53:40 AM
I topped up my tank today and recorded 44.6 mpg, my worst ever figures. Unfortunately, this is going to be the norm from now on with only short trips in and around Edinburgh. The good news is, instead of topping the tank up two or three times a week, this is my first petrol purchase in almost three months.
44.6mpg average over a tank? That would be a good tank full for me, I usually get around 42mpg ish depending on what fuel is in there.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on March 21, 2022, 04:51:23 PM
Today I took the car out for what has become the norm since moving to the outskirts of Edinburgh. We took the cat to the vet in Dalkeith, to get her claws trimmed.
A round trip of 5.3 miles at an average speed of 17 mph and according to the ScanGauge E, 37.3 mpg. That is why I want an EV or PHEV.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Ellied02 on April 04, 2022, 04:25:43 PM
45mpg - mixed driving - whilst trying to get as much out of the little engine as possible!!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on April 04, 2022, 05:28:23 PM
That's what I am getting now with the sort of driving I am currently doing. The figure beside my Avatar is my average over my ownership, never to be seen again now that I have moved to the big city.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: therandike on April 05, 2022, 03:07:56 PM
2008 CVT Jazz SE I get readings from 42-46mpg on the motor way with 65-70mph.

Driving at 60mph on dual crag i get about 50-52mpg

on city drives 40mpg max

I am on 75000 miles

Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on April 07, 2022, 04:26:52 PM
Well, I have now joined the realms of real car ownership. I filled up my tank today and got a calculated figure of 38.3 mpg. Gone the heady heights of 55 - 60 mpg. Now it is city driving, queues, roadworks and rush hour traffic. Short trips and cold weather doesn't help. The good thing is this was the first time I topped up in a month and it only needed 19.33 litres. I even went for 97 RON E5 since I am buying it so infrequently.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on May 08, 2022, 03:58:03 PM
I filled my car up in April and it looks like I will need to top up again in June. I think I can live with the poor mpg at this rate.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: cristispot on July 12, 2022, 08:09:20 AM
04 reg, 1.3 or 1.4 i-dsi, i never know which one is correct, i get 47 mpg on average, 90% on motorway, i do 54 miles everyday in total.

Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on July 12, 2022, 10:41:14 PM
47 mpg on average, 90% on motorway
What sort of speed do you keep to on motorway driving?
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: cristispot on July 13, 2022, 08:14:44 AM
If the road permits it i will stick to 70 mph and 80ish if i am overtaking someone and then back to 70mph.

I have seen someone with the same engine on a Facebook group saying he gets around 500 miles out a full tank but I've never been able to do this. His technique was to drive at ~ 56mph, behind a lorry, accelerate as less as possible and use the engine brake often.( i don't have the patience or will to do this, it's already a slow yet economical car, i might as well drive it normal, not try to squeeze as much mpg out of it)

I can safely do 360 miles, anything after that i am quite nervous i will ran out of petrol.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on July 13, 2022, 07:45:49 PM
I am not on any Facebook group but that is what I used to do and 500 miles from a tankful was common.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: cristispot on July 14, 2022, 01:06:20 PM
Maybe before the E10 petrol, now i feel like it's not quite friendly on mpg.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on July 14, 2022, 08:40:54 PM
I haven't found much difference in mpg between E5 and E10. I have now gone back to using E5 because I do so few miles now. The last time I filled my tank was in May and I still have three-quarters of a tank.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on July 21, 2022, 02:03:43 PM
Today I filled up my tank, not because I needed to, but because this is the car's anniversary and I always work out my year-end audit on a full tank. I was astounded to find that the previous 250 miles, all urban driving, returned a figure of 55 mpg. This was the first top-up since May and since then I have only used the car in and out of the city of Edinburgh. I had to check and double-check as I didn't believe the numbers. Obviously down to the dry warm weather.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on September 20, 2022, 05:18:01 PM
My wife and I had appointments for our Covid booster (the new Original + Omicron) but had to go to Penicuik, about 11 miles away south of Edinburgh. It was a lovely day and a lovely drive, partly on the city bypass but mainly on a delightful section of the A702 into the Pentlands.
As we came home I noticed my ScanGauge was indicating an average of about 80 mpg and it stayed up there all the way back home. Even after the tight manoeuvre, reversing into the drive, the return journey indicated an average of 84 mpg. Unfortunately, that will do little to assuage the figure the next top-up will return due to the almost constant city use that is now my driving norm.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on October 03, 2022, 02:51:39 PM
Had to fill the tank up today and unfortunately, I had to use E10. The supermarkets seem to be dumping E5 from their forecourts. That was my first top-up since July and the calculated figure was 49.2 mpg. Not bad for mainly city driving.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: dbjazz on February 01, 2023, 09:54:53 PM
On the same stretch of motorway at a constant 60mph all the way:
55 mpg outbound
58 mpg inbound

Using super unleaded petrol.

2007 Jazz CVT 41K miles.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on February 01, 2023, 11:37:21 PM
Good numbers. I take it that is from the dashboard display.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: dbjazz on February 01, 2023, 11:56:10 PM
yes - by setting the trip mileage to zero at the start of each run and reading the mpg at the end. Quite difficult to maintain 60mph without cruise, mind.

Are they good figures?  I hope to improve them by blanking the EGR and with the new iridium plugs.  Those runs were with a new upstream O2 sensor.

I've found, with similar tests on previous cars, that super unleaded gives 5% to 10% better mpg, as well as better performance which makes it well worth paying 5%-10% more for.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on February 02, 2023, 09:48:16 AM
yes - by setting the trip mileage to zero at the start of each run and reading the mpg at the end. Quite difficult to maintain 60mph without cruise, mind.

Are they good figures?  I hope to improve them by blanking the EGR and with the new iridium plugs.  Those runs were with a new upstream O2 sensor.

I've found, with similar tests on previous cars, that super unleaded gives 5% to 10% better mpg, as well as better performance which makes it well worth paying 5%-10% more for.
I AVERAGED 55 mpg (calculated) over six and a half years with my Mk 1 Jazz. I also found an improvement using 97 RON but when I worked out the numbers I didn't find it cost-effective. I suppose it depends on where you buy your petrol and the price you pay. I used supermarket petrol but had to buy Shell 97 RON so there was a marked difference in price. I found the car felt smoother on the better petrol but that may have been placebo effect.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: fashionphotography on February 04, 2023, 11:07:29 AM
im wondering where your finding unleaded lol??? or badges as unleaded.. but ive found with E.10 mine has a slightly better economy but on E.5 it runs smoother
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: glenz75 on February 07, 2023, 11:34:58 PM
At the moment my Jazz is doing 40mpg in between fills - mainly city and stop/start driving so not too bad. Once I sort a couple of issues it has then hopefully it might return an even better mpg.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: jaxabin on May 27, 2023, 08:15:06 PM
I'm getting about 48 mpg mostly ring roads and sometimes stuck in traffic according to the odometer. It's my first car so I'm definitely not driving super economically yet so I'm happy with it
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on May 27, 2023, 08:28:18 PM
The "Fibometer" as it is referred to here is a bit optimistic at times. You are best calculating every time you top up. You can use a site like https://www.spritmonitor.de (https://www.spritmonitor.de) or https://www.fuelly.com/ (https://www.fuelly.com/)
SpritMonitor is in English if you select the Union flag.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: jaxabin on May 29, 2023, 05:59:38 PM
The "Fibometer" as it is referred to here is a bit optimistic at times. You are best calculating every time you top up. You can use a site like https://www.spritmonitor.de (https://www.spritmonitor.de) or https://www.fuelly.com/ (https://www.fuelly.com/)
SpritMonitor is in English if you select the Union flag.

Thanks. I made a note of when I filled up so I'll start logging it on paper each time i fill up
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on May 29, 2023, 06:31:57 PM
Thanks. I made a note of when I filled up so I'll start logging it on paper each time i fill up
I do that too!
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: jaxabin on May 31, 2023, 09:41:08 PM
My first ever petrol filling alone!! I went to full tank. 247.8 miles and 28.67 litres at the tank so mpg of about 39.29

I'll hopefully increase that as I get better at driving
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: jaxabin on June 06, 2023, 09:46:40 PM
Filled up again today. 231.8 miles and 20.11 litres of fuel to top up again
gives a mpg of 52.40 which is surprising! This time it was mostly country roads and motorway miles, not too much city driving. I didn't know cars are so much more efficient on faster roads
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on June 07, 2023, 09:06:42 AM
My 2006 1.2S returned a calculated figure of 55 mpg over six and a half years and 62.500 miles. When I moved to Edinburgh and started to do more urban driving, the mpg dropped off considerably.


Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: scratchabout on June 30, 2023, 12:33:27 PM
Distance on each leg 120 miles, bit of town then motorway driving, from the dashboard:
On the way out taking an unnecessary risk on motorway up to 15mph above the limit (not something to be recommended) 43 mpg.
Being a good boy and running along 60-70 something to be recommended) 61mpg.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on June 30, 2023, 02:29:45 PM
Good numbers even though it was from the "Fibometer". Shows you how much petrol you can save by keeping the speed within the limit.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Rocco on July 19, 2023, 08:29:50 AM
I have to admit, I am a pretty economical driver in general, minimal breaking, long stopping distances and no rush to reach the speed limit.  After a 20-mile journey home with the car last night, I turned it off with 67mpg on the dash, although it was had fallen down to 56mpg whilst at 70mph.  Pretty happy with that.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on July 19, 2023, 11:56:42 AM
The best I have had on a trip was 108 mpg but it was ideal conditions and lowish speeds.
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Rocco on July 20, 2023, 08:24:18 AM
The best I have had on a trip was 108 mpg but it was ideal conditions and lowish speeds.

That's near as good as the 109mpg I got when I rolled the car down from the ramps last night.  ;D
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on July 20, 2023, 10:10:11 AM
This is the trip that the figure was achieved over. I used a ScanGauge, which computes the mpg from the fuel fed to the injectors and the mileage covered. I reset it as the video starts and it returned the figure on the display at the end. I was right into hypermiling at the time. The best I ever got, top-up to top-up, was a calculated 70.9 mpg in ideal summer conditions. I always kept my tyre pressures at 35 psi front and rear and checked them weekly.

Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Rocco on July 20, 2023, 11:03:18 AM
A vision of how the roads will look everywhere from 2030  :(
Title: Re: What MPG are you getting from your Mk1 Honda Jazz ?
Post by: Jocko on July 20, 2023, 12:23:46 PM
Just a typical Scottish road!