Extracted from natural gas or derived as a by-product of the petroleum industry. Car LPG is a blend of mainly propane and butane, and is not interchangeable with LPG for barbecues.

Good points

• Less local air pollution than petrol.
• Some reduction in CO2 emissions compared with petrol for a given trip.
• Petrol and diesel vehicles can be converted for LPG use. A government grant of $2000 is available for conversion of an existing private vehicle, or $1000 for the purchase of a vehicle manufactured with an LPG unit. (See www.ausindustry.gov.au or phone 132846 for more information).
• Most conversions enable dual-fuel use; for example, petrol and LPG.
• More than 3200 outlets – more than other alternative fuels.
• Substantially cheaper per litre than regular petrol, because it requires minimal processing and is not subject to excise until 2011.

Bad points

• Made from non-renewable resources.
• Still emits considerable CO2.
• Lower energy content than petrol, which means you travel a shorter distance on the same size tank of fuel. You need about 30% more LPG to go the same distance as petrol.
• Requires expensive car conversion with an initial outlay of $2000-$4000, so it’s more attractive for higher-mileage vehicles. (See www.ausindustry.gov.au for accredited installers.)
• Some new cars are built to use LPG only.
• Some vehicles can’t be converted due to space limitations.
• Need to consider not only the current price of LPG, but what it might cost in future.