"Greasers" are drivers who fuel their vehicles with used frying oil—which used to be a snap to come by for free, thanks to restaurants who were willing to give the stuff away. But the vegetable oil is also a component of biodiesel, and as demand has grown, so has the cost: The market price for grease jumped 70% during the past six months, to about $3 a gallon. What does that mean for greasers? Professional "renderers" are starting to pay for the used oil, meaning many restaurants are no longer willing to just give it away.
Both greasers and renderers have to filter the oil before it can be used; greasers must also modify their cars to run off diesel engines, which can handle the used grease, while renderers clean it up so they can resell it at market price, sometimes to makers of biodiesel. Greasers tell the Wall Street Journal stories of renderers who have wooed their restaurant providers with offers ranging from $15 to $50 for a barrel of grease. Sure, it may not be a lot of profit, "but it's better than when I got nothing," says one bar owner. Adds another manager, "a lot of people don't realize this is a commodity."