Motor racing isn't the greenest of pursuits, I'll admit. It does seem though, that some positive fuel economy advancements are coming from it. Audi are leading the way with their diesel R10 TDI, which recently won the 12 Hours of Sebring. The car has been so successful in recent races that a handicap was placed on the team, reducing the size of the fuel tank by 10% and forcing more pit stops. Audi won the event despite this, and a puncture that cost two laps.
It would be a stretch to call the R10 economical, but any improvement is positive. It's unrealistic to expect everyone to give up high performance cars, so the fact that people are working on fuel efficiency even in this niche market is great news. If Audi were to combine this technology with more sustainable bio-diesel it would be even better, as the Lola B2K did at Le Mans last year, but at least they're on the right track.There are plenty of incentives for manufacturers to invest in green technologies; in a race like Le Mans the less often you have to refuel the greater your chance of winning, and there is also an ecological prize up for grabs, which Audi has previously won. A more cynical commentator may say that It's also helpful to have a green angle for the marketing department to work with.
Hopefully some of these advancements will eventually trickle down from the race and research departments to consumers, just like variable valve timing, direct injection, 5 speed automatics and those little cup holders that spring out when you push the button.
In any case, if you must drive a 200Mph car, then why not buy one that can run on bio-diesel?