Today, kerosene is mainly used in fuel for jet engines (more technically Avtur, Jet-A, Jet-A1, Jet-B, JP-4, JP-5, JP-7 or JP-

. One form of the fuel known as RP-1 is burned with liquid oxygen as rocket fuel. These fuel grade kerosenes meet specifications as to smoke points and freeze points.
In the early 20th century, kerosene was used as a cheap fuel for tractors. The engine would start on gasoline, then switch over to kerosene once the engine warmed up. A "heat valve" on the manifold would route the exhaust gases around the intake pipe, heating the kerosene to the point where it can be ignited by an electrical spark.
Kerosene is sometimes used as an additive in diesel fuel to prevent gelling or waxing in cold temperatures.