Is the MK4 more economical in urban driving?

[peteo48]

When "Which" tested the MK4 Jazz they got an astonishing urban mpg of 91 mpg in real world conditions - better than the WLTP figure. It was less economical on the motorway - much less in fact recording 39 mpg at a steady 70 mph.

So my question is this:

Is the Mk4 Jazz a bit like an EV - in other words is fuel economy better in short urban journeys than it is on the open road?

I struggle to get much more than 40 mpg out of my Mk3 given the short stop/start nature of most of my journeys. I'm wondering if the same profile of journeys in a MK 4 would double that to, say, 80 mpg?

[nowster]

Yes, it can be. I'm getting a mixture of results on local journeys as my area is quite hilly.

Overall I'm getting in the high 60s MPG.

[Bristol_Crosstar]

In speed limit areas you're in EV mode more so fuel consumption is better than at higher speeds. As my trip to the local supermarket is mostly downhill I can sometimes drive all the way there without using the petrol engine.

[Jeff15]

Last week I got 67.5 mpg,  on all sorts of roads.

[Kremmen]

That's why my expected mpg isn't going to be that high.

I do mostly motorway and fast A roads.

[peteo48]

Really useful figures Jazzik. Full hybrids like the Jazz, Yaris etc seem to fit my driving profile completely. I would also benefit from the extra torque.

[richardfrost]

I've been driving my Toyota RAV4 AWD hybrid for four years now. The mpg is impressive considering it's quite a large car and has a 2.5l petrol engine. Last Saturday, driving between central Lancashire and West Yorkshire along a mix of mostly A roads, it exceeded 50mpg! Yesterday, a revving Golf next to me at the lights really irked me so I put the car in Sport mode and floored it. All 2.5l and both electric motors shot me to 40mph a cars length ahead of the Golf. A bit stupid of me but sometimes these whippersnappers need putting in their place! I am a big fan of hybrids.

[Expatman]

The technology of cars are in a rapidly changing environment for the next few years so any decisions buyers make now will surely be overtaken by new developments. All we can do is weigh up the pros and cons of likely vehicles and go with our best guess. Personally I have decided on a hybrid rather than pure electric because the charging systems are too erratic and geographically unevenly spread. Conventional ICE's will become rarer over the next 5 years and further obstacles put in their way in towns etc.

[Hicardo]

anyway, back to the OP question about mpg under urban and other conditions 

- my avg is 62 in Crosstar and I hardly do any urban driving, probably less than 5pct.  25 mile drive in undulating countryside today gave 74mpg one way, and 63mpg coming back. 200 mile motorway trip gave high 50's at 65mph. doing a similar trip this week at 70mph. expecting mid fifties maybe.

perhaps foot to the floor would give you 39mpg, but I think youd have to gun it quite hard to get such a poor consumption. for reference my old Toyota hybrid on a motorway gave around high forties. 

in a few urban situations ive done, I remember the engine is off a lot of the time in the Mk 4. so amazing mpg possible   

[Hicardo]

I should say my avg is brought down by the fact that I do lots of 2 mile trips to local village from cold start, and it hilly. that short trip can vary between 41 and 55mpg depending on whether car is warmed up or not

[Kenneve]

Re The OP question, I suppose it depends on what you are used to.
My previous MK3 would return around 55mpg on my average motoring.
I filled up my MK4 earlier in the week and this morning the gauges were showing 136miles covered of urban/country roads at 71.3mpg.
Today I have covered 240miles taking in M42/M1/M18/M180 at mostly 70mph and the fuel gauge is now down, showing 64.1mpg with 149 miles remaining. All figures from the fibometer.
So yes, it is much more economical in urban driving.

[John Ratsey]

The aerodynamic losses are much less in urban driving due to the lower speeds while the hybrid system eliminates much of the inefficiency of urban driving by (i) recovering most of the energy when the vehicle has to slow down and (ii) having the engine run (when it runs) at maximum efficiency (around 2000 rpm). Hence the typical urban driving cycle is (a) run the engine to get the battery to 70% charge; then (b) run on battery until the charge reaches 30% (which can be a mile or more); then repeat the process. The same cycle happens if the motorway becomes stop-start traffic.

However, I suspect that Which?'s >90 mpg is an exception caused by factors such as (i) then engine and weather being warm; (ii) the battery being at 70% or more charge at the start of the trip; (iii) the starting point being higher than the end point; and (iv) a tail wind. Do an urban circuit with several stops and you'll see the variability but the average should be better than 70 mpg once the engine is warm and provided the weather isn't very cold resulting in the engine doing overtime to provide cabin heating.

[Kenneve]

I think I broke my record today.
Prior to filling up today the gauges where showing 436 miles covered at 64.2 Mpg
The 436 miles included a 240 motorway dash at 70mph, as described in a previous post.
The fill up took 32.37 litres or 7.11 gall, which equates to an actual 61.32Mpg.

I've just done a trip from Solihull to Stratford-on-Avon and return, total distance 37.9 miles.
The A3400 has a 50mph speed limit and there are small sections of 30mph with speed cameras.
Tourist traffic in Stratford was heavy, with much stop/go on the way to the carpark.
The attached photo shows 79.7mpg, which for me is a record.
Probably need to subtract about 3mpg for the Fibometer, but nevertheless a pretty good result.

It would be interesting to know, what other members think is the most economical speed for the MK4, consistent with making reasonable progress. I'm thinking probably around 55-60mph, or when the ICE clutch kicks in?

[richardfrost]

Your profile for the Solihull to Stratford on Avon journey matches closely a journey I made about 10 days ago from central Lancs to West Yorkshire, on which my RAV4 returned best ever fibometer reading in the low to mid 50s. I think it is pretty much the sweet spot for hybrids, gentle ups, gentle downs, lots of coasting or maintaining modest speeds in the 40s. Keeps the ICE running as efficiently as possible and electric drive to the max.

[John Ratsey]

It would be interesting to know, what other members think is the most economical speed for the MK4, consistent with making reasonable progress. I'm thinking probably around 55-60mph, or when the ICE clutch kicks in?

I reckon it's about 45mph - just fast enough for the direct drive to cut in (which, when I first got my Crosstar I discovered was about 43mph using the phone to show the engine revs via a bluetooth OBDII reader). Higher speed increases the aerodynamic drag losses (which increase with the square of the speed) although the Honda video on youtube suggests the best engine efficiency is at around 2000 rpm.

FWIW, the record-breaking Land's End - John O'Groats trip in a Mk 3 was done at 40 mph which, I'm sure, had been figured out to be the optimum speed for fuel economy.