http://www.fueleconomy.gov/feg/flextech.shtml

Flexfuel vehicles are designed to run on ethanol blends of up to 85% (E85). Ethanol is a whole 'nother can of worms as farmers grow corn just to be made into fuel and all other crops become less profitable.

Personally, I go down the big oil + government conspiracy theory path. I know it's possible to make amazing, high performance, low emission, fuel efficient vehicles. It's been done many times in the past but these vehicles never made it into production. Even electric cars have been successful and proven but never produced (watch 'Who Killed the Electric Car' if you don't believe that)

My motorcycle gets 40MPG+, goes 0-60 faster than just about anything on 4 wheels, has a top speed of over 180mph, and runs on 87 octane pump gas. There's more than power to weight ratios going on there.