Frequently Asked Questions

What is LPG?

  • Liquefied Petroleum Gas or LPG is the generic name for mixtures of hydrocarbons (mainly propane and butane).
  • LPG is a colourless, odourless gas heavier than air. A chemical called ethyl mercaptan is added to it to impart a pungent odour to assist leak detection.
  • Automotive LPG is a mixture of propane and butane, while bottled gas used for domestic purposes (such as cooking and heating) consists mainly of propane. For safety reasons, automotive LPG and the domestic grade cannot be interchanged.
  • LPG is gaseous at normal pressures and temperatures but will liquefy readily under moderate pressure or reduced temperature. One litre of LPG equates to 270 litres of Vapour (gas).

Is LPG Autogas safe?
YES: LPG has been used safely in Australia for many decades. The Australian standards for LPG equipment, appliances and their installation and for storage and handling are among the worlds best. Every aspect of the LPG industry is covered by a National Code or Standard and also by similar or additional State Regulations.

How Safe are LPG Autogas Engine Systems?

  • The LPG Autogas system in today’s modern vehicle is designed to be safe: safe in use, safe to repair and safe in a vehicle accident.
  • The Autogas system has a number of important safety features including:
  • A 3mm welded steel pressure cylinder which is stress-tested to many times its normal operating pressure prior to being installed;
  • Two electronically controlled shut-off solenoids (on cylinder and under bonnet) which stop the flow of gas to the engine if the engine stops for any reason;
  • Pressure relief valves for the tank and the system, to prevent any pressure build up that may damage the system, or be hazardous;
  • Double back-check valves to ensure gas tight filling;
  • Sealed compartments and venting around valves and pipe-work to ensure no LPG enters the interior of the vehicle;
  • Approved components to ensure long service life; and
  • The support of trained personnel who comply with rigorous Australian Standards for manufacture and installation of the system, in new cars at the production line, or vehicles retrofitted after purchase.

When will automotive LPG become excisable and what excise rates will apply?

  • Currently there is not an excise on LPG. LPG will remain excise free until 1 December 2011.
  • The excise rates that will apply to LPG used in internal combustion engines will be 2.5 cents per litre from 1 December 2011 increasing in five equal annual steps to 12.5 cents per litre from 1 July 2015 as indicated below:


Table 1: Excise Rates cents per litre @ 1st December 2011
2008 2009 2010 2011 2012 2013 2014 2015
0 0 0 0 2.5 5.0 7.5 10.0 12.5


Is there a national fuel quality standard for automotive LPG?

  • On 1 March 2004, the Commonwealth Government implemented national fuel quality standards for LPG autogas under the Fuel Quality Standards Act 2000 (the Act).
  • The standards are regulated through the Fuel Standard (Autogas) Determination 2003.
  • The levels of propane and butane in autogas are controlled through standards set for the Motor Octane Number (MON) of the fuel and volatility control through the standard for vapour pressure.
  • The Department of the Environment and Heritage (DEH) administers the Act and enforces fuel standards.