Should I convert my car to LPG?

The news that residents parking charges in London will be linked to the levels of carbon dioxide emissions of their vehicles has got us thinking about LPG – Liquid Petroleum Gas.

Those with cars that emit high levels of carbon dioxide will now pay three times more for their parking permits, if they live in the London Borough of Richmond.

Are there benefits in converting to LPG? Are there costs as well as environmental reasons to switch? We examine some of the arguments for and against in this article.

What is LPG?

LPG is a gas in liquid form, so filling your car with LPG is very similar to filling it with petrol or diesel. Built in safety measures during filling prevent spillage making LPG slightly more safe than petrol and about as safe as diesel.

LPG has major environmental benefits as it emits about 20% less carbon dioxide than petrol and less harmful particulates than diesel. This means that LPG powered cars and vans have far less polluting and green house effects than their petrol and diesel counterparts.

Because of major tax incentives, LPG costs about half the price of petrol or diesel – about 46p per litre at the moment. Apparently there is no performance degradation when using LPG, although we haven’t tested this.

There are currently around 1200 petrol stations that sell LPG in the UK so there should be a supplier reasonably nearby to you.

Converting your vehicle to LPG

Converting your car to run on LPG must be undertaken by trained and qualified specialists who ideally belong to the LPGA. They will ensure that your car can be successfully converted and that there are no warranty issues with converting your car in this way.

You will also need to advise your insurance company about the conversion. Generally there should be no premium increases if the conversion has been undertaken by a LPGA approved installer.

Conversion costs vary, depending on your car, however they will be in the £1,500 to £2,000 range. Lets see if this is a wise investment.

Cost benefits with using LPG

Assuming it costs £2,000 to convert your car, and that it normally costs you £50 to fill your tank with petrol, you will need to fill your tank 80 times to recoup the conversion costs.

So if you fill your tank once a week, it will take about 18 months to pay for the conversion costs.

If you own a large “gas guzzling” car with poor fuel economy you will therefore benefit. Convert it and keep it for three years and you will save considerable amounts of money for at least 18 months of that time.

There are other cost benefits too

You can get 100% discounts on the London congestion charge if your LPG vehicle qualifies for the power shift register. At £8 a day, this could save you over £1000 a year if you drive into the London congestion charge zone regularly.

With the London congestion charge zone now extending further west, and with other cities considering adopting similar congestion charges, many people could benefit from these discounts.

Of course congestion charge savings dramatically reduce the pay back times of the conversion costs, so if you drive a 4×4 on the school run in London, you will be making considerable savings in less than a year, and you are helping the environment too.

Other points to consider

Cost savings depend on your car, your mileage and whether you have to pay congestion and parking charges linked to your car emissions. Savings can be dramatic, as we’ve shown and are a no brainer in certain circumstances.

You still have to be close to petrol stations that supply LPG, though you can have your car converted to run on both LPG and its normal fuel, for convenience.

The effect of LPG conversion on the depreciation of your car is an unknown, though it seems sensible to assume that a 4×4 type vehicle would probably depreciate less, particularly with increasing road duty and other green taxes being targeted at these vehicles.

So is there benefit in converting to LPG?

We have looked at the cost benefits and found there to be a strong financial case for converting to LPG, depending on your exact circumstances, and almost certainly for 4×4 drivers in cities, particularly London.

Switching to LPG has very strong environmental benefits so if you want to make an effort to reduce your carbon footprint and are willing to make a financial sacrifice with the conversion costs, or want to drive a large car, then converting to LPG is probably a good idea.


  1. I bought a new Vauxhall Astra van, 51 reg, with a factory fitted LPG/petrol combined power. Over the years until I scrapped the van this year for just under £200 and bought a new Astra Estate, I ran the van almost exclusively on LPG. I think it was 29.9p per litre the first time I filled it. I had very little trouble with the van and, solely because it would have cost too much to pass its MOT (new Cat. and work on the LPG system, decided on a new car.. I am retired but still active and felt that I owed myself a new vehicle and had no use for a van. I got about 30 mpg on LPG but now, with pretty careful driving manage in the region of 40mpg. Petrol here is 127p per litre at the moment and LPG is 67p and I do approx 1500 miles per month so I am seriously considering having an LPG conversion.

  2. I am considerng buyng an lpg converted S class merc. t has been done with a LIMA system and I dont know f this is a multipont system i have been told that you need to have a multpoint system installed in this type pof car is this true and (second question) the system was installe three years ago, what are the maintenance issues with the systems.

  3. You bet its worth it. I’ve done 105,000 in my Mercedes ML320 since conversion without so much as a hiccup. The car was 7 years old when I bought it. I calculate I’ve saved over £13000 in fuel since then — IS IT WORTH IT??? – No Brainer
    Be careful though, seek professional advice though, I was sadvised against converting certain Fords, Hondas, Suzukis – soft valve seats and the WILL burn out after a few thousand miles

  4. Hi there, what is the average price for a LPG conversion at the moment?

    i have just brought a new Jeep grand cheroqee 3ltr diesel and am wondering if it is worth it?

  5. I would like to convert my Renault Grand Espace into LPG i am heading to Poland is it ok to convert my veh. there or its not worth the cost converting is almost a half. please advise

    look forward to hearing from you guys

    email me direct at


  6. LPG in the UK has gone up from 42p a litre in 2008 (when I bought my LPG car) to 80p a litre. I can’t see any benefit in owning an LPG car anymore and it seems the UK Government are trying to turn the screw on absolutely everyone, even though our cars aren’t polluting like petrol and diesel ones do. This was the original excuse for petrol and diesel tax hikes, but the recent spike in LPG prices only confirms that we are being ripped off and lied to once again.

    • David,

      Specifically in relation to your comment, If you do the arithmatic, you will notice that depsite the fact that LPG is now 80p in some places (although it is 61p in others!) your saving is still greater than it has ever been.
      When your LPG was 42p a litre, petrol was between 85-90p, making your saving approx 43p a litre. Today, even if we use the worst case scenario of LPG being 80p, petrol is around £1.35 so your savung is 55p. Please do not make the error of mistaking a higher LPG price for a lower representative saving as it just isnt true.

      I hope you will still consider LPG for your next vehicle?

  7. Hi

    I have an auto 4 cylinder 2005 nissan pulsar. Would that be wise to convert it into LPG ? I heard a lot that it wont make any difference as its a 4 cylinder.

    I look forward to hear about this

  8. Whilst LPG is ok, after just under 5 years of conversion, valves in my cylinder head burnt out because of using LPG

    The repair bill was almost £1400 and the problem was solely down to using LPG as my main fuel source. There was not enough lubrication / cooling going on in my cylinder head and it caused cylinders to blow 🙁

    Worth bearing in mind. Doubt my car car will get converted.

  9. No ,not at all… I have LPG on two family cars, at first, almost 7 years, and it s really good investment. There are almost 20% gasoline driven cars in south-east europe converted to LPG!!! I didnt heard any case of dangerous situations. People did crush test with gasoline and LPG cars, and guess what? Gasoline tanks was burned, but LPG reservoir didnt, becouse it was made by heavy steel… So, consider!

  10. I have Jeep model 97, 4100 cc, 6 cylinders and I want to convert it to LPG but I heard from many different peoples that it will damage my engine in about 2 years… that true ??? pls advice me with information based on real science

    I hope someone email me with full answer on this email

    thanks so much

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