The sanctioning body for Formula One racing, the FIA, is currently examining options for new engine rules for 2011 and beyond. Over the past year they've been throwing out various proposals including hybrid powertrains. The latest proposal is a switch from the current 2.4L V-8 formula to 2.2L turbocharged V-6s.
The current engines have no rpm limit and many are thought to run at speeds approaching 20,000 rpm although the new proposal would limit that to 10,000 rpm. The new engines would also switch from running on 102 octane "gasoline" to some kind of biofuel. The FIA wants to reduce costs and make the engines more environmentally friendly. Since a switch to ethanol could end up with even more powerful engines due to the turbocharging, maybe they will make the jump to biodiesel instead. Formula One could have some very interesting times ahead.