Diesel engines can run on just about anything, including used cooking oil. Just ask ole Willie Nelson and his bio Willie deal. As a result, an entire industry is emerging to provide brave 'biodiesel' pioneers with the ingredients for petroleum-free motoring.

It turns out biodiesel is not a new idea. When Rudolf Diesel introduced his signature engine at the 1900 Paris Exposition, he said two words as he started it: "Peanut oil." He designed his engine so farmers could grow their own fuel. Most diesel engines were indeed run on vegetable oil until the 1920s, when the petroleum industry promoted a gasoline byproduct as diesel fuel. Maybe we should all be Amish. It seems that the ideas of the past keep coming back.

With all that said, it might sound romantic to help clean the environment by having your car smell like French fires, but it is worth the physical aggravation to help save the air and money.

We take a look at a couple in Elmira, New York who really have their cars "cooking."