LPG conversion vehicles - Are they worth it?

by DannyUK

I’ve been reading a lot recently about LPG conversion and making my unleaded car into an LPG car.

LPG stands for Liquified Petroleum Gas (or alternatively spelt Liquefied Petroleum Gas) and is a cheap alternative way of running your car. But is it worth it?


This isn’t a sponsored post, or even one extolling the benefits of a product I have tried and either love or hate. LPG is merely something I like the sound of. With only approximately 200,000 cars in the UK running on LPG, which is only a tiny fraction of the estimated 31 million cars that are registered in the UK, it’s quite niche at the moment.

What is LPG ?

The main use of LPG in the UK is for heating and cooking, but also as the type of propane that is used for autogas which is what I’m interested in. When stored under pressure it becomes a dense liquid.

I drive a lot these days, and the idea of being able to fill up with LPG at 70p per litre as opposed to £1.30 a few months ago, or 64p per litre compared to £1.08 that I pay for unleaded at the moment. So what’s stopping me from going straight for a conversion now? Well there’s a few things.


First of all is the cost. You have to shell out almost £1,500 to get your car converted, and the process takes three days. The argument here is that you’ll make the money back over time given the reduced cost of filling up your car, but it’s still a payment that needs to be made in advance. I’ve got a quote from a nearby supplier and including VAT it’s £1,800.

The reason for the expense is that it involves installing a second fuel tank in your car, with a second fuel gauge. There’s also a suggested annual maintenance fee to take into account of between £25-£50.

As MoneySupermarket says: “Once installed, you simply fill up your new tank at a service station forecourt as you would your petrol tank. There’s no danger of putting in the wrong fuel or overfilling as the LPG hose has a unique nozzle and an automatic shut-off valve.”

The system, once installed, still allows you to use unleaded petrol if you need to. In fact, it’s recommended to use unleaded for short journeys.

My car does 44.1 mpg according to official figures.  Using the savings calculator at DriveLPG.co.uk in September I worked out, using 69.9p as the average price for LPG and 128.9p as the average price for unleaded (both taken from petrolprices.com) that it will take two years of driving to get that money back (assuming I do 20,000 miles).

As of February 2015, using 64.9p as the average price for LPG and 108.1p as the average price for unleaded - taken from the same sources above - using the same annual mileage, it will save me £617 per year, meaning it will take almost three years of driving to make my money back.

Obviously, the sell-on value of the car should increase due to the conversion, but we I haven’t taken that into account.

LPG savings

LPG saving vs cost of unleaded petrol - using rough prices and mileage.



I called my local Peugeot dealership who I bought my car from and who do my servicing and MOT and they categorically stated that they would not service the car or do the MOT if it was converted to take LPG.  This struck me as unusual, but the girl I spoke to went away to check and called me back a few hours later with the information.  It’s something to take into account if you are thinking of having it done.

Local LPG stations

Recently Radio 4 covered the topic of LPG vehicles and a representative stated that everyone in the UK had a service station that sold LPG within 5 miles from their home.  She went on to say that although this wasn’t anywhere near as many as unleaded or diesel selling stores, it was still enough to be able to refill without having to travel far out of your way.

Naturally I looked up my local service stations and - based on Google Maps - my closest is actually 5.1 miles from door to door.  The 0.1 mile difference made me laugh and almost caused me to send a tongue-in-cheek email to the BBC.

The sparseness of suppliers is shown on the map below, and makes filling up yet another consideration into whether you should convert your vehicle.  Personally, I’d argue that it’s worth it even if you drive a few miles out of your way. Not only that, but I’ve noticed that LPG seems more readily available at motorway service stations where it seems to hold the same price as it does on regular forecourts.

LPG stations in Essex - GetLPG.org.uk

LPG filling stations in Essex - including a distinct lack of them in the centre of Essex’s only city


The conversion process is available on most cars, though not every car is suitable for the process.  Most importantly for me is the fact that it doesn’t take up any additional space in the boot of the car.

Autogas.ltd.uk explains it well:

The choice of LPG vehicles in the alternative fuels market is second to none with most petrol engines suitable for an LPG conversion.

Nearly all autogas vehicles are dual fuel meaning they can run on either LPG or petrol and as such have two independent fuel systems & tanks. Of course, to make the most significant money and emissions savings, users of LPG cars run on the fuel as often as they can.

LPG fuel tanks can be located beneath the boot floor, in the spare wheel well in place of the spare wheel, or mounted under the chassis, in the case of vans & 4×4 vehicles, resulting in no loss of valuable boot load space.

Most LPG kits are completely integrated with the existing fuel and engine management systems of modern vehicles resulting in a reliable and efficient autogas system.

How it’s done

Quite simply, a secondary fuel valve is put into the car.  The conversion process takes approximately three days, and I have read in various places that you may be entitled to a reduction in road tax (though from what I could see it was only £10 per year saving)

As it’s officially considered a conversion, you also need to let your insurer know, though there should be no additional cost (and equally no reduction in premium!)


I’m still undecided as to whether to convert my car or not.  On the one hand, the cost savings would be welcomed.  On the other hand, there are so few places locally to me where I could stock up with LPG that I run the risk of paying for the work and then primarily using unleaded due to laziness, which would defeat the object of converting.

There’s also the concern about the ongoing maintenance of the vehicle.  Peugeot have already said that they would no longer service my car, and although I am happy to get it serviced elsewhere, it seems a shame to have to move from the manufacturer service.

If anyone reading this has had the conversion done on their car, I’d love to hear your input as to how it has worked out for you.

A list of approved LPG installers can be found here.

You can find out where to buy LPG and your local LPG stockists here.


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