First understand its not a new fuel for operating on vehicles, LPG vehicles have operated in high numbers in NSW since early 70s, with increasing safety measures and operating systems which deliver gas efficiently to your vehicle. The strict safety standards adopted for the Australian standard A.S.1425, has ensured that there are far more safety regulations and failsafe features in your gas vehicle than the original petrol system. Servicing of the vehicle is only marginally different than the original petrol version, and can normally be done by any licensed mechanic.

The LPG system usually has only one small filter in the engine bay, this is a relatively inexpensive filter usually less than $10.00, recommendation in most LPG service schedules are to change this at approx. 20,000 klm. This may vary around Australia as quality of fuel may vary. As this filter is on the pressure, or liquid side of the gas system, this simple procedure does need to be done by an LPG licensed mechanic, to ensure that the liquid side of the system maintains its integrity and no gas loss will result. The filter is rarely a cause of problems in NSW operating conditions, some vehicles operating on gas can have filters removed for the first time at 100,000 klm and show little evidence of failing, however the small cost will prevent the unusual situation of a blockage. One characteristic of LPG in operation is that it produces higher amounts of nitrates in its combustion process, most of this by-product will be expelled through the exhaust, however, some will end up in your sump/oil and create combinations such as nitric acid, in small quantities this is not a problem, but if oil change periods are extended this can be very harmful to your engine. Most oil companies do provide an LPG rated oil that will combat this by-product, it is unfortunately, usually a standard mineral based oil, mostly 20w40 rated, not really an efficient oil by today’s standards, most oils theses days are of a higher rating (SJ, or SL, or SM rating), if kept within the normal maintenance period, the more developed semi, or full synthetic oils will return much better fuel economy, with excellent engine protection.

Tuning of LPG is a very minor extension from the normal petrol tune, minimal adjustments to mixture can be normally attained in minutes, however, because the efficiency of LPG compared to petrol is slightly less, more attention needs to be given to items such as spark plug gaps, and resistance of spark plug leads, premature failure of these items often results in backfire, which may cause damage to the air intake system. Most failures of the actual LPG system itself, such as the gas mixer, or the gas converter are usually attributed to other problems.

The Airod converter/mixer system has minimal moving parts and subject to very little wear as opposed to some similar LPG systems fitted to vehicles which after about 2 years in service become higher maintenance. Failure of the gas converter may be an issue, after 2 to 3 years, indications are, after normal resetting by the mechanic, frequency of this procedure will increase until tune may only be maintained for a number of weeks, indicating the converter needs re-kitting or replacing, in a large number of cases like this we need to check for other influences which may have attributed to premature failure, this is seen commonly when the engine is at higher mileage, and the wear factor has begun to cause an oil vapour to enter the engine intake system, this vapour tends to condensate in the gas systems vapour lines, causing premature failure of the diaphragm or converter membrane, this is a fault that without major engine overhaul to reduce this oil vaporisation can only be rectified as a temporary measure, by replacing parts damaged by the oil vapour, which in turn will deteriorate prematurely.


In general, most things will be covered by your initial hand over orientation from the installer. Some items to note about the safety of LPG gas are more awareness is needed on still dry days, gas is heavier than air it will hit the ground and either stay at a low point or flow downhill, most of these quantities are minimal and will dissipate, however, it is always good to be aware of the characteristics of the fuel, windy days will dissipate gas quickly, and rain or water will absorb LPG, making it inert (in respect to volume), when filling it is inevitable you will have a minor amount escape when attaching or removing the nozzle. Be aware that at this point it is a liquid, on entering atmosphere it will freeze, this in turn can cause serious burns when contacting the skin. It is not common, but possibly at some stage you may try to fill your gas tank, and although the tank may be near empty, you will not be able to get more than a few cents into the tank without it cutting out, this seems to happen mostly on hot summer days, the automatic shut of valve may have stuck or the float has jammed, drive a couple of klm more and at another service station you find there is no problem, it is likely the fault was in your tank and is temporary, don’t dive in and blame the service station operator straight off, it may not do this at all, or you may find it will happen 2-3 times a year, but be aware it can happen, if it is repetitive it will need attention.

Running Dual-Fuel Vehicles

The benefits of LPG once you begin to operate one become very obvious, the cost savings tend to make you not want to use much petrol, however, most late model systems will still start quicker on petrol than LPG, so the newer systems are designed to start on petrol then switch over to LPG for normal operation. Problems we need to be aware of are that the longer we keep the same old tank of fuel in the vehicle it will lose its octane rating, and eventually become acidic, and can cause considerable damage to the fuel pump and injectors. Once these parts have failed it can lead to expensive repairs to return them to normal operation. It is best to keep your petrol tank above half, and at least once every month or two, run for 100-200 klm on petrol to keep the fuel “new” it will also help balance out the octane problem if you use premium fuels.

Keeping the tank above half is always good practice with late model EFI vehicles, as lower levels in the tank will uncover the fuel pick up, and even if only for a second or two air entering the fuel pump will not cause a loss of power or engine miss, but a fuel pump even for a split second will rely on fuel to lubricate it, these constant few seconds of picking up air into the fuel pump will result in premature failure of the pump, more unwanted costly repairs. LPG is a “dry fuel” it has no lubricating properties, the upside of this is in normal petrol vehicles, petrol is continually washing the cylinder walls of lubricating oil so lower engine (bottom) wear through lack of lubrication is normal, in LPG vehicles, this is not the case, the effect of petrol on the cylinder walls no longer happens so the oil control rings are able to sustain lubrication to the cylinder walls much better, reducing lower engine wear.

The downside of the dry fuel is in the cylinder head area, valves and valve guides are subject to a higher percentage of wear, and this can be reduced by the fitment of a valve saver lubrication system, relatively inexpensive, (approx. $100.00 to $120.00 installed on most vehicles) and will reduce the amount of valve wear. L.P.G. fuel is effectively 15% less efficient than petrol, under normal circumstances this is not noticeable, however, when towing, or with a more than normal load, such as 4-5 adults, or luggage space loaded, this does become noticeable, it may be necessary to use gears more often( staying in lower gears longer, not using overdrive in automatics etc) and if towing or using in terrain where you know that hills may be an obstacle, use petrol for a short time, although this seems to be a negative to the savings, other normal operating periods should more than make up for the inconvenience experienced on some occasions.

Going on a Trip

LPG is now widely available at over 3,000 outlets around Australia, the Australian LPG Association have an internet site very helpful in planning any trips, and identifying where you can fill up all around Australia. Contacting Elgas, Vitalgas, Unigas, Bp, Caltex, Mobil, Shell Autogas, or any of the suppliers and they are usually more than happy to send you a booklet of where all their outlets are. For example, a trip from Sydney to Brisbane via Pacific Highway gives you 109 Autogas outlets, the furthest distance between outlets is 72 klm. To plan your trip, Visit the LPG association website at, and use their handy trip planner.

We are happy to give you advice based on your specific needs – simply give us a call on (02) 9521 1655