Everything you need to know about converting your classic to LPG

Once upon a time, not all that long ago, LPG was seen as the ideal alternative to petrol and diesel engines as drivers battled with ever-increasing fuel costs.

Today, petrol and diesel prices are still on the up, but most of the media attention surrounding an alternative to traditional fuel is fully trained on electric and hybrid vehicles.

But despite disappearing under the radar, LPG is still a viable alternative, with around 170,000 LPG vehicles registered here in the UK.

Here we discuss everything you need to know about LPG, converting your classic car to run on LPG and what the conversion would mean for your classic.

What is LPG?

LPG stands for liquefied petroleum gas and is a type of ‘liquid gas’. Also known as butane and propane gas, LPG can be used as fuel for a number of different things, from barbecues to cars.

Technically, LPG is a by-product of the processing of natural gas and used to be simply burnt off and wasted before someone discovered just how versatile it was as a fuel.

In order to be used as a fuel, the gas is subjected to pressure or cooling which turns it into a liquid and allows it to be stored in a vehicle’s fuel tank.

Why is LPG not more popular?

That’s a good question. LPG is quite widely used in homes and businesses throughout the UK, but when it comes to powering cars, the take up of LPG has been less than remarkable.

Currently, only around 1% of vehicles in the UK are powered by LPG despite the fact that LPG fuel typically costs around half the price of petrol and diesel on the forecourts.

One of the biggest reasons that LPG vehicle sales have failed to take off is lack of enthusiasm from successive UK governments — as is often the case with alternative fuels — despite the government’s own ambition to ban the sale of new petrol and diesel vehicles from 2040.

Lack of investment in the necessary infrastructure, coupled with no significant tax-breaks and a dearth of publicity, has meant that many motorists in the UK simply don’t know that LPG remains an option for them.

Where can I buy LPG?

According to the UK trade association for the LPG industry, UKLPG, there are currently around 1,400 fuel stations across the UK that offer LPG

While that might sound quite a lot, there are a total of 8,500 stations in the UK, meaning that if you’re travelling in more rural areas with an LPG car, there is a significant chance you might not find a retailer.

However, there are a number of websites that map LPG stations which makes it easier for motorists to find their local garages, and a lot of the big chains like Shell and BP do provide it.

How much is it to convert a car to LPG?

In short, the cost of having your car converted to LPG isn’t cheap, with the average price being around £1,200, depending on the vehicle being converted and the system to be used.

Each conversion takes around three days to complete and drivers are advised to use UKLPG-approved installers to ensure that the LPG system supplied has been distributed by an accredited manufacturer.

How is a car converted to LPG?

During the conversion, a number of different components will be installed into your car, most notably the tank itself which will normally be installed in the boot — often in place of the spare tyre to minimise loss of load space.

Other things added include a gas injection LPG system with gas fuel injectors and its own ECU, fed by an LPG vaporiser that turns the liquid gas you put in into a gaseous gas. An LPG fuelling point will also be added.

What are the main benefits of LPG?

One of the most pressing benefits of LPG is the fact that it offers significant savings on fuel bills as LGP retails at around half the price of petrol and diesel.

LPG is also a lot greener than either diesel or petrol, with around 20% less carbon emissions and almost no particulate emissions at all.

Crucially, LPG cars are predominantly “bi-fuel”, meaning that they can run on both petrol and LPG so if you’re caught short and can't’ find anywhere to fill up you can always pop in some petrol.

What are the main problems with LPG?

Despite the cost savings it brings, LPG is actually quite a bit less fuel efficient than petrol — around 20% less efficient, which could mean a range of around 150-200 miles per tank.

The relative lack of availability of LPG is also a problem for some motorists, and although this is countered somewhat by the fact that bi-fuel engines can also run on petrol, there’s little point converting to LPG if you’re just going to fill it up with petrol.

Can I convert my classic car to LPG?

In short, yes. Depending on the make and model of your vehicle, the price may well fluctuate somewhat from the average conversion cost of £1,200 – but being converted to bi-fuel remains a possibility for the clear majority of classic cars.

Should I convert my classic car to LPG?

Whether you decide to convert your classic car to LPG depends entirely on personal choice for the vast majority of classic car owners.

If you are tempted by lower fuel costs and fewer harmful emissions you’ll need to weigh up the initial cost of the conversion itself as part of the equation. The chances are that eventually, you will end up saving money from the conversion if you drive enough, however, if there aren’t many LPG refuelling stations near you, or you don’t drive your classic that often, chances are the savings won’t be quite so noticeable.

Another thing to consider if you happen to drive to France a lot is the fact that LPG cars are not currently allowed to use the Channel Tunnel, although they are perfectly fine to be ferried across to Calais the old-fashioned way.