Why can biodiesel be put into a car that runs on unleaded or leaded fuel?
Vehicles that run on gasoline have spark-ignition engines. These engines use spark plugs to ignite the fuel. They are designed to use very thin, explosive fuel. Diesel engines are compression-ignition engines. Instead of a spark plug, they use super-compressed air to ignite the fuel. They are generally heavier, sturdier engines that are designed to run on thick, viscous fuels like vegetable oil-derived biodiesel. For alternative fuels for gas engines, look at ethanol, wood gas, natural gas, or methane. The Biomass Energy Foundation has info at http://www.webpan.
