Liquefied petroleum gas or LPG is a flammable mixture of hydrocarbon gases that can be used as a fuel for vehicles. It was first produced in 1910 by Dr. Walter Snelling by refining petroleum derived from fossil fuel sources. The first commercial products appeared two years later and it now currently provides about 3% of the energy consumed without soot and very few sulfur emissions.

LPG is referred to as autogas when used as fuel for vehicles. Autogas has a lower energy density therefore fuel consumption is higher as opposed to petrol. It is considered as a green fuel since it decreases exhaust emissions.

Autogas is very popular in Australia because it is cheaper compared to petrol in urban areas. Autogas is acknowledged as Australia's most widely accepted alternative fuel and has grown a great deal in recent years. Currently there are over 600,000 autogas-powered vehicles in the country and over 3,000 refueling stations most especially in urban areas. Most taxi companies use autogas because of its affordability and efficiency. Cars perform better and there is less damage to the environment.

In order to abide by environmental policies, many companies with vehicle fleets have begun to use autogas as an alternative to traditional fuels because it can run almost any vehicle, cheaper, and have much lower environmental impact than petrol or diesel.
There are two types of autogas-powered systems today: dual-fuel and dedicated.

Dual-fuel systems can allow the vehicle to run on unleaded petrol as well as LPG and is ideal for situations where flexibility of fuel sources is an advantage such as remote rural areas. Meanwhile, the dedicated systems are solely used for LPG and advantageous when containing running costs by a company of vehicles.

Modern autogas-powered vehicles are safe to use and repair as well as in vehicular accidents. The LPG tanks are rigorously tested to ensure that they can withstand enormous impact forces without deforming and leaking thereby preventing car explosions. These vehicles are also ensured with sealed compartments to ensure that no LPG enters

LPG Australia is the leading body that represents the industry to all levels of government in Australia. It aims to support the national interests for a lower carbon economy. The association focuses on the values and benefits of autogas as an essential alternative to traditional types of fuel. LPG Ausrtalia estimates that the saving made by running 15 autogas-powered vehicles is equivalent to the purchase price of one new vehicle.

Advantages of autogas conversions

• Autogas is cleaner and less polluting compared to other forms of fuel since it reaches the engine in pure gas form resulting in an improved air/fuel mix. The resulting combustion is quieter smoother compared to petrol.
• Autogas emissions are cleaner as opposed to petrol and greenhouse gas emissions from the exhaust are far less than with petrol.
• The life of the engine is extended since there is no residual acids and carbon deposits left during combustion.
• Maintenance of the vehicle is minimal and does not cost much.