Briante said there are about 100 million gallons of waste restaurant oil generated annually.

CNN: Can vegetable-oil cars save the world?

Kuhn is part of what Lee Briante, a spokesman for Greasecar, the largest purveyor of veggie fuel conversion kits, says is a growing market segment.

CNN: Can vegetable-oil cars save the world?

"In the first few years it was, I don't want to say hippies but ... now it's folks doing it for the economy of it, " said Briante.

CNN: Can vegetable-oil cars save the world?