Is it worth LPG or should I buy a diesel?

[sam871]

Hello,

Could do with some advice regarding this.

I have recently changed jobs requiring 20k miles a year, mostly A roads and city. I currently own a 1.4 turbo petrol which I cant say is the most economical (properly returning mid to late 30's). I have read in certain articles that LPG is only worth the investment on larger engines however with this mileage I'm not sure if selling up and buying a diesel is a better option. Local fuel prices are 68p (LPG), 115 (Petol) 123 diesel. Any advice on this subject or past experiences would be much appreciated .

Thanks

[alorotom]

Depends on the cost of the change really rather than exclusively on the fuel comparitor unless you are proposing a cost neutral change / direct swap

[healey2]

Lpg is also meant to be very bad on the engine unless done by manufacturer

[Haltamer]

Which turbo petrol is it? Being a 1.4, it sounds like one of the more modern economy focused petrols, in which case I'd have thought you could nurse it up to ~40, 50mpg (Attainable with an NA engine) just by being lighter with the go pedal.

A diesel is probably the way to go with that mileage, but depeding on the value of your current car you could look at trading in to a hybrid or similar, given you're looking at city mileage.

[anonymous-user]

We recently bought a 3.2 6 Cylinder Volvo XC90 with the aim of converting it to LPG. In fact its booked in for next month.

Thoughts were if we bought the diesel one and found it thirsty we would be stuck however if we bought the petrol version and converted it then it would work out as a very cheap car to run. Not to mention the fact that diesels are slowly being banned from most German cities...

My other car is on LPG and has been for close to 3 years. (2005 Lexus LS430) It averages 25mpg on gas which makes it very cheap to run at the pump however the yearly MOT (at least in Poland is more expensive with LPG on board) and the system requires a separate service, Fuel filters etc.

The local Lexus dealership takes care of the main service and MOT and we have a trusted LPG installer locally. (LPG is so commonplace that the Lexus dealership don't even bat an eyelid)

Tanks are homologated for 10 years at a time and usually have to be replaced after 10 years (Again not sure on UK laws)

Living on the continent and travelling extensively around Europe I think LPG is fantastic and would never consider a diesel again. Installed correctly and maintained correctly you shouldn't lose any power nor should you suffer valve seat recession (Lexus engine has been checked yearly since installation). Modern systems are very clever indeed. Switchover between fuels is seamless even at full power. No Hesitation nothing.

Installed badly and you will destroy your engine and wallet above and beyond any savings.

When we travel to the UK I found finding LPG a pain and also filling LPG a pain with the Bayonet style filling adaptor. (Italian dish or Acme as used in Europe is far superior)

If you have a local filling station that stocks LPG then I'm sure it will be a good investment. I think the British fear of LPG is purely down to the few bad installations people have experienced whereas in continental Europe LPG is very much mainstream with everything from 900cc shopping trolleys to supercars running on the stuff (No stigma attached to it google LPG Ferrari, Yes it happens )

Go for a Polish or Italian system (Stag or Tech) and you won't go far wrong. If you can find a Polish or other Central European installer locally then its well worth it as they really know their stuff and seem to have a better understanding of it due to how common it is.

Good Luck

[Don Phil]

As above, find a good installer and you'll be fine. Have a chat with one to run through what would work best for you and your car.

I like LPG, its clean (check the oil 10k miles after a service, 10k it'll be like new!), it's cheap and once you get used to planning where/when you need to fill up it really is a no brainer if doing tons of miles and keeping the car for a while.

It is harder to sell a car with a conversion, though just takes someone to be looking for one and you're fine. Plus as above you will need the system servicing and filter changing but no great cost compared to savings.

The bayonet fitting in the UK is standard here and after a couple of goes is easy enough.

[underphil]

healey2 said:

Lpg is also meant to be very bad on the engine unless done by manufacturer

depends on the car, some engines are fine with it

BMW N52 is good example

[kurt535]

older the engine, the better? yank small blocks work very well.

[anonymous-user]

Its down to the valve seats apparantly. Most modern engines have hardened valve seats as standard and therefore theres no detrimental effect at all. Some don't so a flashlube system is needed. If in doubt run a tank of petrol through for every 5 tanks of LPG. (Its good practice anyway to stop your petrol injectors from gumming up)

Either way installed correctly and maintained properly there shouldn't be any more wear than running on petrol. Maintaining an LPG system is far cheaper and less annoying that repairing, replacing, cleaning, adding fluid to the emission reduction systems on a modern diesel.

Our LPG service is around 20 quid a year.

[Slushbox]

" mostly A roads and city."

The question will be which cities? UK cities are still permitting Euro 6 diesels, though there are double parking fees for DERVs in places like Westminster.

'Economy', as mentioned, requires a cost-neutral switch from the current car to the alternatives. If you spreadsheet it, you might find running the 1.4 into the ground is the cheapest option.