Diesel fuel, also called diesel oil, fuel oil (historically), or simply diesel, is any liquid fuel specifically designed for use in a diesel engine, a type of internal combustion engine in which fuel ignition takes place as a result of compression of the inlet air and then injection of fuel without a spark. Therefore, diesel fuel needs good compression ignition characteristics.
The most common type of diesel fuel is a specific fractional distillate of petroleum fuel oil, but alternatives that are not derived from petroleum, such as biodiesel, biomass to liquid (BTL) or gas to liquid (GTL) diesel are increasingly being developed and adopted. To distinguish these types, petroleum-derived diesel is sometimes called petrodiesel in some academic circles. Diesel is a high-volume product of oil refineries.
