Biodiesel is a domestically produced, renewable fuel that can be manufactured from new and used vegetable oils, animal fats, and recycled restaurant grease. Biodiesels physical properties are similar to those of petroleum diesel, but it is a cleaner burning renewable alternative. Using biodiesel in place of petroleum diesel significantly reduces lifecycle carbon emissions. Research shows that it also reduces emissions of toxic air pollutants in older on-road vehicles and in many off-road applications.