What MPG are you getting from your Mk1 Honda Jazz ?

[culzean]

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.

[Jocko]

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.

[MartinJG]

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.

[Jocko]

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!).

[Jocko]

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.

[MartinJG]

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?

[Jocko]

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).

[MartinJG]

Jocko

This is total commitment. Dedication to perfection and nothing less!

[Jocko]

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.

[DesmoDan]

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.

[Jocko]

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.

[guest7218]

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

[sparky Paul]

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.

[RScorpio]

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+?

[Jocko]

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.