Gasoline or petrol is a petroleum-derived liquid mixture consisting mostly of aliphatic hydrocarbons and enhanced with aromatic hydrocarbons toluene, benzene or iso-octane to increase octane ratings, primarily used as fuel in internal combustion engines.Most Commonwealth countries or former Commonwealth countries, with the exception of Canada, use the term "petrol" (abbreviated from petroleum spirit). The term "gasoline" is commonly used in North America where it is often shortened in colloquial usage to "gas". This should be distinguished in usage from genuinely gaseous fuels used in internal combustion engines such as liquified petroleum gas (which is stored pressurised as a liquid but is allowed to return naturally to a gaseous state before combustion). The term mogas, short for motor gasoline, distinguished automobile fuel from aviation gasoline, or avgas. The word "gasoline" can also be used in British English t