Just done 8 km (5 miles) without using any fuel at all.
Easy. Fill the tank at the top of a mountain pass. When it levelled off a bit and used some fuel I was still getting 285 mpg.
The downside Going up there were times the engine was working hard and I was only getting 15 mpg
. Same with a few , erm, enthusiastic' overtakes . But 200 km later, doing 90kph,occassionally more ,it still averaged out at over 80mpg.
This is real world usage. If a truck can get up hill, so can the jazz,with ease. And make the descent without needing B mode for additional engine braking or stressing its brakes. Get real here. Even in the lake district, North wales ,scotland and other hilly places (or indeed the alps)there are not many hills a truck cant climb. A word of warning. ALL cars can overheat their brakes on a long descent if you are not cautious. You walk down a steep hill. If you try and run down you will lose control and fall over. Controlled descent from the top, simples. 1 in 3 and 1 in 4 hills are a bit of a novelty, and rarely very long. Model T fords from the 1910's and 1920's might need to go up in reverse ,which has lower gearing ,but the Jazz will eat them for breakfast and go up no problem at all. . If its a bit noisier than normal for a few minutes,or seconds, in very exceptional circumstances, thats no reason to miss out on is normally exceptional quietness and fuel economy.