With a few modifications, you can run a diesel vehicle on vegetable oil to power your car or truck. People across the country are using conversion kits to retrofit their vehicles. Others are taking a do-it-yourself approach. Some burn free waste vegetable oil from local restaurants; others burn clean straight vegetable oil. But there’s a catch: Technically, it may not be legal. Originally published as "Would You Use Veggie Oil to Fuel Your Vehicle?" December 2007/January 2008 MOTHER EARTH NEWS.