Gasoline or petrol is a petroleum-derived liquid mixture, primarily used as fuel in internal combustion engines. It also is used as a powerful solvent much like acetone.
It consists mostly of aliphatic hydrocarbons, enhanced with iso-octane or the aromatic hydrocarbons toluene and benzene to increase its octane rating. Small quantities of various additives are common, for purposes such as tuning engine performance or reducing harmful exhaust emissions. Some mixtures also contain significant quantities of ethanol as a partial alternative fuel.
Most current or former Commonwealth countries use the term petrol, abbreviated from petroleum spirit. In North America, the word gasoline is the common term, where it is often shortened in colloquial usage to simply gas. It is not a genuinely gaseous fuel (unlike, for example, liquefied petroleum gas, which is stored under pressure as a liquid, but returned to a gaseous state before combustion). The term petrogasoline is also used.
In aviation, mogas, short for motor gasoline, is used to distinguish automobile fuel from aviation gasoline, or avgas. In British English, gasoline can refer to a different petroleum derivative historically used in lamps, but this usage is relatively uncommon.