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Autogas for Australia

LPG vs Petrol Savings Calculator

One of the biggest advantages of LPG powered vehicles is the savings realised on fuel costs. 

Autogas is the safe, inexpensive way to run your car, especially as the family budget seems to get more and more stretched!

Please use the calculator below to estimate your fuel cost savings

Just insert the number of kilometres you drive per year and the cost of petrol and LPG in your area:


How to Beat the Petrol Price Cycle

Don’t you just hate having to fill up your tank in a week when the petrol and diesel prices are high? 

Think how much you could save each year if you could always time your purchases for the lowest priced days. 

There is a way!

LPG conversionsIf you are like me, driving a considerable distance every week, you frequently find yourself in a position where you need to purchase petrol or diesel while prices are at the high point of the price cycle. 

A few years back, when the price cycle was just one week, most people had the cruising range, on a single tankful, to make it through. 

Now the price cycle can be over 2 weeks long, exceeding the length of time you can go between fill-ups.

LPG Gas Conversion Cost - Dual Fuel is the Answer

One of the unheralded benefits of having a dual fuel vehicle is the extended driving range provided by having two fuel tanks. 

With both the petrol and LPG tanks filled, cruising ranges of 1000km or more are not unusual.

So, unless you drive an extraordinary number of kilometres every week, you can cruise from low price point to low price point with a dual fuel car or truck, without having to refill in between.

Almost all vehicles fuelled by unleaded petrol can be converted to LPG operation at a reasonable cost. 

These dual-fuel LPG systems allow a vehicle to operate on either LPG or petrol and can frequently double a vehicle's range. 

The petrol tank still remains in the car and the driver can switch from gas to petrol or vice-versa.

LPG Conversion MPG - Miles per Gallon or Kilometres per Litre

LPG conversion MPG is dependent on many things, however, the key items include:

  • The efficiency of the engine

  • The weight of the vehicle

  • Gear ratios

  • Average trip speed

  • Traffic density and delays

  • Driving style

  • The percentages of Propane and Butane in the LPG, although the differences would be small

With the exception of the percentages of the gas mixture, the remaining items are the same regardless of whether you are running the vehicle with LPG or petrol.

LPG Average Mileage

As explained above, each vehicle could have different fuel efficiency.

In general, a car will consume about 20% more LPG, by volume.  However, LPG is typically much cheaper.

Assuming that the LPG is about half the price of petrol, the savings still amount to about 40%.

It is important to note that whilst mileage is expressed in miles per gallon, metric efficiency is usually measured and expressed in litres per 100 km.

LPG is the Forgotten Fuel

Somewhere along the way, Australians forgot about LPG. 

LPG is still typically 50 to 65 cents per litre less than petrol. 

Also frequently unnoticed, LPG pricing doesn’t bounce up and down, like petrol and diesel, with the weekly price cycle. 

It is much more stable.

Converting to LPG typically results in hundreds, if not thousands of dollars of savings every year, depending on your vehicle usage. 

This number could be even higher if you factor in avoiding the purchase of petrol during the high priced days of the cycle.

Dual Fuel Conversion

LPG conversion technology has come a long way in the last few years. 

Liquid LPG injection offers advantages over older vapour injection systems.

A vehicle with a state-of-the-art liquid LPG system produces at least the same amount of power when running on LPG, as compared with running on petrol.

There are over 100 engineered Liquid LPG Kits for domestic and imported cars available from a number of Australian suppliers. 

There are also many specialist installers around the country who can install these kits on your car. 

The time required to install an LPG system varies. 

A typical family sedan, with a single boot-mounted tank, should take only one to two days.  

A large four-wheel drive, with multiple tanks, might take two to three days.


Calculator Assumptions:

Fuel costs based on fuel consumption figures for Falcon XT petrol sedan of 9.9L/100km and Falcon XT EcoLPi sedan of 12.3L/100km (both tested to ADR81/02, combined cycle). 

Data sourced from Ford Australia. 

Actual fuel consumption and savings will differ by vehicle.



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