'Green' concept cars of 2007

Unlike flex-fuel vehicles currently on the market, the BioPower 100 can run on E100, 100 percent pure ethanol, as well as E85, which is 15 percent gasoline, or pure gasoline. Other flex-fuel vehicles can't take pure ethanol.

Ethanol contains less energy than gasoline. But it has a very high 106 octane rating, meaning that it can withstand higher compression than even premium gasoline.

Taking advantage of that higher compressibility, the BioPower 100's turbocharged 2.0 liter engine produces an amazing 300 horsepower. Computers adjust the compression ratio downward when sensors detect the car is running on E85 or pure gasoline.

Since ethanol can be made from plants, it also has the advantage of not adding any C02 to the atmosphere when burned. It only returns to the atmosphere C02 that was recently removed by the plants used to create it.