Whenever James Nestor needs to fill the tank of his diesel Mercedes, he doesn't go to a filling station and pay $3 a gallon; he visits his favorite Indian restaurant in downtown San Francisco and gets takeout -- free jugs of used cooking oil.
"I eat here just about every day," Nestor says. "That's how I know they have the best grease."
Nestor's car burns the same vegetable oil used to cook everything from french fries to egg rolls.
A small but growing number of people, particularly in the San Francisco Bay area, know that diesel engines were originally designed to run not on petroleum-derived diesel, but peanut oil.
"We've been running it on waste vegetable oil from a Japanese restaurant," says another local devotee, Jill Fuss. "So we haven't paid for diesel in over a year."
Brian Friedman and Brooke Stewart make their living converting modern diesels to run on vegetable oil. Converting requires some extra hoses, a larger fuel filter and a preheater to thin out the fuel before it is injected into the engine.
Friedman and Stewart have a waiting list.
"It's not a hippie experiment anymore," Friedman says. "It actually works and it works really well."
Straight vegetable oil is different from what's known as biodiesel, a mixture of vegetable oil and alcohol that will run any diesel engine.
Used cooking oil does produce an exhaust that smells like the restaurant it came from. You can tell Thai and Mexican fuel.
It's a small disadvantage for something free in a world where oil is nearly $70 a barrel. You almost never have to go to a gas station.
"Well, I had to use a gas station to put air in my tires last week," said another user, Denise Lindsay.
It may seem a little crude. But the point is, it's not oil. These pioneers of grease-burning cars believe that a source for the alternative to the ever-increasing cost of petroleum fuels is all around us.
And you can get a good lunch there, too.
ABC News' Brian Rooney in Los Angeles originally reported this story for "World News Tonight" on Sept. 18, 2005.