About LPG:
Liquefied petroleum gas (LPG), is a flammable mixture of hydrocarbon gases, most commonly propane, butane, and propylene. However, the latter two typically comprise 5% or less of the mixture.
LPG is used as fuel gas in heating appliances, cooking equipment, and vehicles. It is increasingly used as an aerosol propellant and a refrigerant, replacing chlorofluorocarbons in an effort to reduce damage to the ozone layer. When specifically used as a vehicle fuel it is often referred to as autogas.