Well you could try rationing,
but unless there's some kind of national emergency, where people see a real, obvious danger to themselves and all that they hold dear it is a dead duck of an idea. Sorry to say that. But, instead of rationing what you could do is impose European fuel efficiency standards on the US auto Industry. Increased efficiency is the only way to reduce fuel consumption that might work in a democracy that does not feel threatened. It might even save Detroit as a world car-building centre. Greater fuel efficiency would also make some point to using biofuels. Currently, the technology that produces biofuels is inefficient, using that technology to convert food-stuffs into fuel is only feasible if the fuel produced is used in more efficient engines, otherwise it will be a profligate and highly inflationary waste of natural resources.