Jet fuel is a mixture of hydrocarbons that varies widely based on the petroleum source used to make it. Jet fuel is defined as a performance specification rather than a chemical compound because of this variability. The range of molecular mass between hydrocarbons is defined by the requirements for the product, such as the freezing point or smoke point. The two most common types of jet fuel are Jet A and Jet A-1, which are made up of kerosene, a product of extremely refined oil. Jet B is another type of jet fuel that is used in extremely cold climates. It is made up of 30% kerosene and 70% gasoline, giving it a freezing point of -60°C, but it is more dangerous to handle than other types of jet fuel. Jet fuels are typically made by blending and refining various crude oil petroleum distillation products such as naphtha, gasoline, or kerosene in order to meet specific military or commercial specifications. The exact composition of jet fuel is not specified by chemical composition because of the great variability in the concentrations of major components of crude oil.

In summary, jet fuel is a mixture of hydrocarbons that varies widely based on the petroleum source used to make it. The two most common types of jet fuel are Jet A and Jet A-1, which are made up of kerosene, a product of extremely refined oil. Jet B is another type of jet fuel that is used in extremely cold climates, but it is more dangerous to handle than other types of jet fuel. Jet fuels are typically made by blending and refining various crude oil petroleum distillation products such as naphtha, gasoline, or kerosene in order to meet specific military or commercial specifications.