Autogas

Autogas or LPG is liquefied petroleum gas (LPG) used as a fuel in internal combustion engines in vehicles as well as in stationary applications such as generators. It is a mixture of propane and butane. Autogas is widely used as a "green" fuel, as its use reduces exhaust emissions by around 15% compared to petrol. One litre of petrol produces 2.3 kg of when burnt, whereas the equivalent amount of autogas (1.33 litres due to the lower density of autogas) produces only 2 kg of when burnt. CO emissions are 30% lower, compared to petrol and by 50%. It has an octane rating (MON/RON) that is between 90 and 110 and an energy content (higher heating value—HHV) that is between 25.5 megajoules per litre (for pure propane) and 28.7 megajoules per litre (for pure butane) depending upon the actual fuel composition. Autogas is the third most popular automotive fuel in the world, with approximately 16 million of 600 million passenger cars powered using the fuel, representing less than 3% of the total market share. Approximately half of all autogas-fueled passenger vehicles are in the five largest markets (in descending order): Turkey, South Korea, Poland, Italy, and Australia. In countries where petroleum spirits is called petrol rather than gasoline, it is common for autogas to be simply referred to as gas. This can be confusing for people from countries where petrol is called gasoline, as they often use gas as an abbreviation of gasoline. In the United States, autogas is more commonly known under the name of its primary constituent, propane. In 2010 the Propane Education and Research Council adopted the term "Propane Autogas" to refer to LPG used in on-road motor vehicles. In the UK the terms LPG and autogas are used interchangeably. In Australia and the Netherlands, the common term is LPG. In Italy and France, GPL (an acronym for gas di petrolio liquefatto or gaz de pétrole liquéfié) is used. In Spain the term GLP (gas licuado del petróleo) is used.