Diesel fuel is produced from various sources, the most common being petroleum. Other sources include biomass, animal fat, biogas, natural gas, and coal liquefaction. Petroleum diesel, compressed air. European (EN **0 standard) road diesel has a minimum cetane number of *1. Diesel fuel is more efficient than gasoline because it contains *0% more energy per gallon than gasoline. But there are a few kinds of diesel fuel: Standard diesel fuel (sometimes called diesel oil) comes in two grades: Diesel #1 (or *-D) and Diesel #2 (or *-D). The higher the cetane number, the more volatile the fuel. Most diesel vehicles use fuel with a rating of *0 to *5.
