06 Aug 07
Button: unlikely green hero
There are two things racing drivers do that you can copy, only you're after economy rather than speed. Take the shortest line through corners so you don't have to slow down as much, and drive more smoothly. The smoothest racing drivers are often the quickest (providing they're in the right car).
Down hills, leave it in gear and take your foot off the throttle. The injectors turn off, so you're not burning a drop of fuel. Coasting in neutral is less economical because the ECU thinks you're stationary and so fuels the engine to idle. On a hill the engine is being driven by the wheels.
Tricky, of course, but the canny driver anticipates by selecting the right gear to maintain a constant speed up hills. Bogging down in third and having to move to second needs more revs and so burns more fuel. Remember: momentum management.
Hills need forward planning
Sharp steering movements create heat in the tyres and you literally scrub off speed. Heat is bad. It means all that precious petrol energy is being wasted. Same goes for braking. Heat in the pads is energy you paid for.
Those hard-to-achieve fuel consumption figures are carried out over a gentle town route, followed by an equally sedate country jaunt (although they never leave the lab). Manufacturers know this and tune their cars to perform frugally over this period. Rev hard and you're out of that economy zone.
