Car Choice: Converting a luxury car to LPG may not save you money

Roger Wood is planning to buy a large German luxury saloon and have it converted to run on liquid petroleum gas (LPG), which costs half as much as petrol. Roger wants guidance, although he has set his heart on the Volkswagen Phaeton. He wonders if that is the right model to buy and what the running costs would be on this sort of vehicle.

A car for the head

Just at the moment, choosing a large luxury car with a large thirsty petrol engine is actually quite sensible. Not only are these types of cars cheap, because of low demand and high depreciation, but they can be more cost-effective to run if converted to gas. However, that is likely to cost around £2,000, so Roger needs to do some sums. At least the half-price LPG fiscally boosts fuel economy from around 20mpg to 40mpg. Although Roger never mentioned a budget, to get a good example he will need to pay more than £10,000. On this point though, a car that new would have cost in the region of £50k and is always going to involve maintenance bills that are commensurate with a vehicle of that value. So you need deeper than average pockets when buying a car like this. Personally, I don't rate the Phaeton as a luxury car because it has the badge of a people's car.

A car for the heart

There are no shortage of luxury car options and for sheer dependability I would opt for the Japanese Lexus 430. However, Roger is specific about having a German model, although their complexity makes them expensive to fix. The BMW 7 series and Mercedes S Class are particular culprits, while the Audi A8 may be a bit dull for Roger. He said that he liked the Phaeton because it seems so different. However, if he really wants to be different then the Maserati Quattroporte is probably the answer. This is the most achingly beautiful four-door luxury saloon since the original Jaguar XJ6. Although £70,000 new, it is possible to pick up five-year-old examples in the £25,000 bracket. The engine is excellent and Ferrari related. Care is required when buying any hyper-expensive car, so Roger needs to talk to a specialist. One I visited recently – ADG Sevenoaks (01732 835351) – know these models inside out and they will also know if an LPG conversion is a sensible thing to do.

Looking to buy?

Please write to Car Choice, Features, Independent House, 191 Marsh Wall, London E14 9RS, or email James Ruppert at, giving your age, address and phone number, details of the type of vehicle in which you are interested and your budget.