Hello, I hope everyone is well.
As an update, I have done just over 1,000 miles in my Jazz now, which has resulted in 3 full tanks of petrol.
Observations:
1. I could never really get more than about 32 litres into my tank
2. The on board computer MPG vs. real world tank to tank method seemed to vary by 6% to 11%
3. The very best I could manage, driving like an absolute saint was a real world 52.3MPG (on board screen showed 56.4, so a difference of 8%)
4. The journeys were all very similar - some congested stop start traffic but also some A roads with cruise control on 40mph due to roadworks and average speed cameras
5. My average for the 3 tank fulls is as follows;
48.5MPG (screen showed 51.3MPG)
52.3MPG (screen showed 56.4MPG)
50.5MPG (screen showed 56.1MPG)
Summary: the Hybrid Jazz in mixed conditions, in mild weather, does a real world 50MPG