500 miles on a tankful.

[Jocko]

As I have posted elsewhere, I have found that on an incline I see better instantaneous mpg when climbing in 5th gear than if I change down to 4th. I have a ScanGauge E fitted to my OBD2 port, and it is the best thing ever for improving fuel efficiency, when a car does not have onboard instantaneous mpg display.

It shows when car is in Deceleration Fuel Cut Off mode, which is a must for getting good fuel consumption, as well as letting you know when you are using a lot of fuel and when you are saving fuel.
The display is user configurable, with a bar graph showing how well you are doing against your current average. As you can see I have mine set for instantaneous mpg and journey average, but you can display coolant temperature, intake air temperature, Manifold Air Pressure (as a vacuum gauge tells you), in fact, any two from eighteen parameters you can display. It records and displays a range of data from the current trip, today, previous day, this tank and even an estimate of miles until tank is empty. It also displays and resets OBD codes, when required. At just under £100 I found it money well spent.

[sparky Paul]

I spend a lot of time in 5th, the engine is so flexible on the jazz and will happily pull from low revs.

In fact, I have to stop myself being lazy sometimes, it's not good for the bottom end bearings making the engine work hard from 1500 revs, or even less.

[Jocko]

it's not good for the bottom end bearings making the engine work hard from 1500 revs, or even less.

I never ever floor it in 5th. Just let the revs pick up as they wish.

[Jocko]

As you can see from this hp/torque curve, the 1.2 Jazz develops the same torque at 2000 rpm as it does at max power at 5700 rpm, with maximum torque at 2800 rpm. A very flexible engine.