What is an LPG car?

November 24, 2022 by

Wondering what an LPG car is, or if you should consider getting one? We have all the details

An LPG car has the ability to run on liquefied petroleum gas. LPG cars can be cheaper to run than petrol cars as LPG is significantly cheaper than unleaded, and most petrol engines can be converted to run on LPG. But there are a few points to consider before you head out to get an LPG conversion done on your car.

What is an LPG car?

An LPG car is one that has been designed from the factory to run on liquefied petroleum gas, or has (more commonly) been converted to take LPG by an aftermarket conversion company. They are sometimes referred to as dual fuel or Bi-Fuel cars as they can switch between LPG and petrol. In the past it was an unharnessed by-product of the crude oil refining process, but it has since been used as a versatile fuel with a relatively low environmental impact.

LPG contains a mix of hydrocarbon gases and is used as a fuel for a variety of applications from cooking to heating, refrigeration and to power cars. In mainland Europe (and to a lesser extent in the UK) LPG is known as Autogas, and filling an LPG car requires a similar process and takes about as much time as filling a normal petrol or diesel car.

How do LPG cars work?

LPG cars have a secondary fuel system which requires filling from a dedicated LPG pump; these can be found at around 350 petrol stations around the UK.

The LPG is stored in a pressurised fuel tank in liquid form as it turns into gas when exposed to the atmosphere. This tank will be separate from the conventional fuel tank, and will commonly be located under the boot floor. LPG tanks are often known as ‘donut tanks’ due to their shape, and frequently sit in the well where a car’s spare wheel would normally sit.

LPG tanks typically sit under the boot floor

You can switch between LPG and petrol manually, but the system will automatically switch over to petrol once the LPG tank is empty. There’s also a secondary fuel gauge for the LPG fuel tank.

Pros and cons of LPG cars


  • Potentially lower running costs
  • Less harmful to the environment
  • Negligible difference in power output (Newer systems claim a slight improvement)


  • Adds weight to the car
  • Installation costs may take years to recoup
  • Far fewer LPG refilling stations than petrol stations
  • LPG system needs regular servicing
  • Road Tax savings are just £10 per year
  • LPG tank often reduces cargo space

Are there any new cars that run on LPG?

LPG (Bi-Fuel) cars were quite popular in the late ‘90s and early 2000s, partly because of a government incentive which covered some of the conversion costs. The scheme ended in 2005 and the number of LPG conversions dropped dramatically.

Bi-Fuel cars are still popular in Europe, but in the UK Dacia is just about the only manufacturer to offer LPG powered cars from new. Models offering Bi-Fuel engines in the Dacia range include the Sandero, Sandero Stepway and the Duster.

Can you convert a car to LPG?

Yes, most combustion cars can be converted to LPG. This requires the installation of an LPG fuel tank (usually in the boot) and fuel system as well as modifications to the engine’s Electronic Control Unit (ECU). An LPG fuel filler will be installed as well, usually in the rear of the car.

The Dacia Duster and Sandero can be had as Bi-Fuel models, running on both petrol and LPG

An LPG fuel tank gauge and LPG/Petrol switchover button are installed inside the car. LPG systems will switch over automatically to petrol once they run out of gas, but the button allows you to override this feature if necessary.

It’s more of a challenge to convert diesel cars to run on LPG as diesel ignites under pressure alone, where petrol and gas also need a spark. This requires a small amount of diesel to be injected into the combustion chamber along with the LPG to ensure that the mixture ignites.

The average cost of an LPG conversion is between £1,500 and £2,500. The exact amount depends on the installer you use and your specific make and model of car.

Can I save money with an LPG car?

LPG is much cheaper per litre than petrol, currently costing about 50% less per litre. However, fuel efficiency drops by approximately 20%, which limits the savings.
Take a look at this example to see what the differences are:

Average petrol price per litre 164.1p
Average mileage travelled per year 10,000 miles
Average fuel economy in UK 38.8mpg
Total petrol used 1166 litres
Total Cost per year £1913,41
Average LPG price per litre 0.755p
Average mileage travelled per year 10,000 miles
Average fuel economy on LPG 31mpg
Total LPG used 1457 litres
Total Cost per year £1,100

Using an average annual vehicle usage scenario, you can save just over £800 per year running on LPG. That would see you recoup your installations costs in around 3 years. 

Is an LPG car right for me?

LPG cars can yield running cost benefits, but they aren’t always the right choice for everyone. Unless you buy a brand-new Bi-Fuel car, the conversion costs may take years to recoup before you see any savings. LPG systems also require servicing every 12 months which will add to the overall ownership costs.

There are also far fewer LPG filling stations around, most sources state that between 1,200 and 1,400 are currently operational in the UK. In comparison there are approximately 8,400 petrol stations. 

Remember that the LPG is stored in a fuel tank in the boot and will take up some of your luggage space. Some claim that running on LPG lowers power output slightly, while Dacia claims a small increase in power on its LPG-powered cars. In either case, the driving experience should be largely similar, although the extra weight will have an impact on braking and handling, especially in smaller cars.

An LPG conversion is right for you if you:

  • Have convenient access to an LPG fuel station
  • Don’t mind the reduction in boot space
  • Are happy with the LPG conversion costs and intend to keep the car for several years
  • Like the fact that LPG is more environmentally friendly than petrol

An LPG conversion isn’t right for you if you:

  • Drive a very fuel-efficient petrol car
  • Need all the boot space you have
  • Like to change cars every few years
  • Don’t have an LPG station located nearby
  • Don’t want the extra hassle of an annual LPG service 

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