Biodiesel vehicles are designed to run on biodiesel, a renewable fuel made from natural oils, fats, or greases. This type of fuel can be produced from sources like vegetable oil, animal fat, or recycled cooking oil. Biodiesel can be used in its pure form or blended with conventional diesel, making it compatible with most existing diesel engines. Using biodiesel helps reduce greenhouse gas emissions compared to traditional fossil fuels. It can also improve air quality by lowering levels of harmful pollutants. Many automakers offer vehicles that are compatible with biodiesel, promoting a more sustainable transportation option.