What Car? Q&A - How would I convert my car to LPG?

Q: How would I convert my car to run on LPG, and would it save me money in the long run?
Phillip Saunders

A: Liquefied Petroleum Gas (LPG) is a natural hydrocarbon fuel made up of propane and butane. Most petrol-engined cars can be converted to run on LPG, and most systems allow you to switch between LPG and petrol, so called dual-fuel.

Seek guidance from a Liquefied Petroleum Gas Association (LPGA) approved installer. They should be able to advise you on the best system to suit your car and needs.

By using a registered installer, the work should be done to a set standard, you will find it easier to get your car insured, and you should qualify for any discounts and exemptions, such as the London Congestion Charge. You can check the list of registered installers by visiting www.boostlpg.co.uk. Typically an installation can cost between £1500 and £2000 depending on car and the exact components used.

On average, a litre of LPG costs half that of diesel, and you can expect to reduce your fuel costs by roughly 40%, due to the lower fuel duty paid on LPG. Using a Vauxhall Vectra 1.8 (with a manual gearbox) as a comparison, a 1000-mile journey would cost you roughly £61 running on LPG, or £104 running on petrol.

If your annual mileage was 12,000 miles, you would save £513 a year.

If you have a low annual mileage, or don’t intend to keep your car for very long, you will probably not recoup the expense of the LPG conversion. Vehicles with large engines, such as off-roaders fitted with V8s, tend to make more sense as LPG-powered cars. You could consider buying a car already converted, although check that any work has been carried out by an approved supplier.

Vauxhall is the only manufacturer to sell new LPG and petrol dual-fuel vehicles (Vectras, Astras and Corsas). The premium for having a factory dual-fuel Vauxhall is roughly £2500. So, using our 1.8 Vectra example, you would need to cover 59,000 miles before you started saving money.