Vegetable oil similar to the stuff you use to cook your food may one day fill your car?s engine. Researchers at the U.S. Department of Agriculture have developed a chemically modified version of the edible oil that shows promise as a cleaner, renewable alternative to petroleum-based motor oil, while enhancing its protective properties. Veggie motor oil could eventually be produced cheaper than petroleum-based oil and may help reduce this country?s dependence on foreign oil, the researchers say.