That means it can run on either gasoline or E85 ethanol, a blend that's 85 percent ethanol and 15 percent gasoline. Ethanol is an alcohol-based fuel made from plant products.

Ethanol doesn't cost less than gasoline and it offers slightly poorer fuel economy. The advantage is that it's not a petroleum product. It can be made from plants grown right in the United States.

For now, at least, E85 gas pumps are rare on the populous east and west coasts. The fuel is relatively easy to find only in the corn-growing American midwest.

So, for now at least, flex-fuel vehicles from GM, Ford and Dodge are burning gasoline most of the time while drivers wait for E85 pumps to sprout on the coasts.