The sky-high price of crude oil is scaring everyone.
Biodiesel has Hollywood backers like actress Julia Roberts and Morgan Freeman, is sung about by country star Willie Nelson but also meets the political correctness of the American right wing which has made the campaign against imported oil a mantra.
"It's better for the engine, way better for the environment, it's cheaper, but it depends how you price your labor," said Dan Goodman, an entrepreneur in residence at the University of Maryland Business School who runs his Mercedes on biodiesel.
There are two ways to get on the biodiesel bandwagon, Goodman said.
Either you change the engine and just put in waste oil, which would not be strictly legal in the United States, or you can modify the fuel into biodiesel, which is legal and works in any diesel car.
Biodiesel plants are a boom industry in America, but thousands now make fuel in their garages from the oil left after frying french fries or scrounging around restaurants and food facto