I have a little experience of super-economy driving. Last autumn I drove the Mercedes B-Class fuel cell car from Brighton to London and managed to get to the capital with the fuel meter reading ‘0.98’. Merc’s fuel cell guru said anything under ‘1.0’ was good going.
Economy driving is pretty straight forward. No acceleration, no hard braking and taking advantages of hills. So you’ve got to feather the accelerator and brake and look well ahead.
I left the Autocar offices late in the evening and with a fairly smooth run home, though taking in Kingston hill, Roehampton Hill and East Hill in Wandsworth, managed the 12 miles with the Infiniti’s trip still reading 79 miles to empty.
The return trip at lunchtime encountered much heavier traffic, but with judicious use of the Infiniti’s shift lever, I dropped the car into neutral and coasted at every opportunity. (Interestingly. it was the first warm morning of the year and the estimated range quickly jumped from 74 to 95 miles), Back at Autocar, the range was still at 79 miles.
To cut a long story short, I had the car for another evening and after another 24 miles, I handed it back with a range of 74 miles. Of course, the range was calculated on my two day’s driving average, so jumping in and flooring it, would have caused the calculated range to plummet.
Even so, it’s an example of what can be done. And the carmakers are already on to this. BMW is testing an autobox with a ‘coasting’ feature that allows the car to exploit its forward motion and downhill roads and bowl along in neutral.
The extraordinary VW XLR1 concept I drove in Qatar (which, when running on just the two-cylinder diesel engine, is good for 155mpg), spent a great deal of time in coasting mode. The engine only seemed to burst into life when I need acceleration.
There’s much pleasure to be had - and skill needed - for super-eco driving. But you can be sure that the cars of the future will be doing it all automatically. Which is quite a depressing thought.