Average UK Autogas price: 61.7p 107.7 115.0
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An LPG autogas tank installed in the spare wheel well on a vehicle

Vehicle LPG conversion

Save costs & go green –
Our guide to converting your vehicle to run on autogas LPG

Once you have decided that an LPG converted vehicle is for right for you, you will need to find a suitable LPG system for your vehicle and a UKLPG Approved Installer to fit it to your vehicle.

Choosing a suitable autogas LPG system & installer

Most petrol powered cars and light commercials can be converted to run on autogas LPG. If you already have a petrol powered vehicle, the chances are you could convert your vehicle immediately and start to enjoy the financial and environmental benefits of LPG power. There are many systems available from many manufacturers, however not all systems are suitable for every vehicle.

It is recommended that conversions are carried out by a UKLPG Approved Installer. Approved companies comply with set standards, training and examination of installers as well as a thorough inspection process that has government approval. These approved installers will be able to advise you on the best system for your particular vehicle and needs. Find out more about the scheme here.

The process of converting an existing petrol powered vehicle to run on LPG is relatively simple and takes approximately two days to complete when done properly.

The average cost of converting a 4-cylinder vehicle to run on LPG should be around £1,200 – £1,500 (prices may vary depending on vehicle type, age, condition, specification of conversion kit and is intended as a guide only). The average motorist covering 20,000 miles per annum should be able to recover this initial investment within two years. Check out how quickly you could be making savings by using our savings calculator.

The LPG system explained

Modern LPG are a sophisticated as the petrol fuel system installed at the factory by the vehicle manufacturer. An LPG system consists of a storage tank, fuel lines, fuel pump, injectors and ECU (electronic control unit).


As LPG is stored as a liquid under pressure, tanks are designed to withstand high impact and extreme temperatures. To allow for product expansion LPG tanks must be filled to a maximum of 80% and fitted with an over fill protection valve. Tanks should be permanently mounted in the vehicle typically in the boot, spare wheel well or under the chassis.

LPG tanks are available in single-hole and a four-hole varieties. With a single-hole tank, one multi-valve controlling both LPG going into the tank during filling and LPG leaving the tank when the vehicle is running is fitted. This set-up results in a relatively slower-fill rate as the LPG passes through a shared valve into the tank. With a four-hole tank, separate valves are fitted for the LPG passing into the tank when filling and LPG leaving the tank when the vehicle is running. This set-up results in a relatively quicker fill up as the LPG passes through a dedicated valve into the tank.

Filler Point

The vehicle filler point should be permanently mounted to the vehicles body in a convenient spot typically close to the petrol filling cap. In the case of 4×4 vehicles the filling connector may be mounted on the tow bar attachment or low down on the vehicle bumper. Different countries have different fittings for LPG refuelling – to find out more, visit the ‘Refuelling outside the UK‘. The standard vehicle fill connection in the UK is the Dutch ‘bayonet’ fitting.

Fuel switch & gauge

Nearly all LPG vehicles are dual fuel meaning they will run on either LPG or petrol, switching seamlessly between the two fuels whilst in motion at the flick of a switch or when they run out of LPG. This switch is usually mounted conveniently on the dash and may also be integrated with the LPG fuel gauge.

Engine components

Looking under the bonnet you may notice the subtle additions of the LPG fuel system. These will typically include (depending on the vehicle and system) the LPG injectors, vaporiser, LPG fuel lines, additional valve lubrication and ECU.


Converting a vehicle to run on LPG is classed as an engine modification and as such you will need to notify your insurer. Most insurance companies will insure an LPG converted vehicle provided the vehicle is listed on the online UKLPG Vehicle Register. You should check the individual requirements of your insurance company before having a vehicle converted. This can usually be done with a simple phone call.


You should also notify DVLA that your vehicle has been converted to run on LPG as it is a mechanical change from when the vehicle was first registered. By registering the vehicle with DVLA as alternatively fuelled you may be entitled to a reduction in Vehicle Excise Duty (road tax). For more information, visit the ‘Financial Benefits‘ page.