Biodiesel is a clean, renewable fuel produced from vegetable oils, such as soybeans, or animal fats. Pure biodiesel is nontoxic and biodegradable. B20 is a mixture of 20 percent biodiesel and 80 percent petroleum diesel and can be used in almost all diesel engines without modifications.

Ethanol is a high octane, domestic and renewable fuel made from plant sugars. For vehicle use, ethanol is blended with gasoline in blends of up to 10 percent (E10) or 85 percent (E85) ethanol. Ethanol burns cleaner than petroleum gasoline and reduces the emission of carbon dioxide and a variety of pollutants that contribute to ozone levels.