Gasoline, obtained by fractional distillation of oil, has been modified with the evolution of the oil industry and internal combustion engines.

Hydrocarbons, components of gasoline, are members of the paraffin, olefin, naphthenic and aromatic series, and their relative proportions depend on the oil and the production processes used.

Today, gasoline exits from refineries are made up of carefully balanced mixtures of these hydrocarbons to meet engine performance requirements.

A gasoline for consumption is composed of a mixture of two, three or more components obtained in different refining processes, and may also receive the addition of other compounds such as toluene, xylenes, anhydrous ethanol, methanol and other special additives for specific purposes, including: antioxidants and anti-knock agents.