LPG, possible downsides?

Author
Discussion

7SS

Original Poster:

579 posts

223 months

Monday 27th July 2009
quotequote all
I'm currently toying with idea of venture into bangernomics with a cheap & cheerful 4x4 for towing & general workhorse duties.

Interested in the idea of LPG but having done some research on the forums I see some posts suggesting there are risks to to the engine. I can't see much elaboration on what the issues may be though.

Anyone know what the possible problems are? Are any engines more likely to suffer, ie alloy blocks worse tha iron? Any conversion kits worse or better than others? Do the conversions typically leave a minuscule petrol tank making them inconvenient in areas where LPG supply is sparse?

Cheers


7SS


JumboBeef

3,772 posts

178 months

Monday 27th July 2009
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I have a Disco V8 with twin underslung LPG tanks (so it still has it's original petrol tank). I've had it for two years now and covered about 30,000 miles.

In that time I have had no problems at all with it and enjoy filling it up at 49ppl smile I can't tell the difference between LPG and petrol when driving it, from a power point of view.

dudleybloke

19,916 posts

187 months

Tuesday 28th July 2009
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lpg burns cleaner that petrol, doesnt soot as much, and your engine oil will be in MUCH better condition and will last nearly twice as long between changes. the only downside is you cant go on the eurotunnel!

kjmac

561 posts

234 months

Tuesday 28th July 2009
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I converted my 6.0 Monaro to LPG at the start of the year and so far so good. The converter did a good job and there's no noticeable difference between LPG and petrol performance, something I verified by hammering the car down the runway at bruntingthorpe at over 150MPH.

It's a BRC multi-point system with a 4-hole tank in the spare wheel area. 62 litre tank with a gas capacity of 50 litres. At 15/16mpg commuting the range is 180 miles, on a cruise it's just over 210. If you run the tank dry it auto-switches to petrol. Sadly the later Monaros also have the petrol tank in the boot, hence why I wasn't able to put a larger cylinder in. On petrol I get 19 mpg commuting and 25/26mpg on a cruise, so petrol gives me a range of 250 miles - 320+ miles between refiling.



Filler mounted in plastic bumper.

Slightly raised boot floor.

Tank

Fuel gauge and override switch hidden in mobile phone cubby hole.

LPG injectors

Vauxhall have continued to honour the car's warranty, including replacing a faulty rear main seal.

Overall I reckon that LPG works out at 2/3 the price of petrol. The only fly in the ointment so far is that when starting a warm car I can sometimes get an error code showing for the long-term fuel trim. I think the car's just getting confused. I'll get it sorted at some point, but as the Monaro doesn't have a MIL lamp it doesn't really bother me. If anyone knows how to reset the long term fuel trim on a fat Holden please let me know.


Edited by kjmac on Tuesday 28th July 00:34

k2lvn

63 posts

182 months

Tuesday 28th July 2009
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Got a 5 series bmw converted to LPG and had no problems with the LPG side of things, my old man has had a 4.0 Jeep grand cherokee and a Jag Estate 2.5.
Pretty sure his next car will be LPG too and given the choice of two similar cars, side by side, I'd be taking the 49ppl route each time smile

mybrainhurts

90,809 posts

256 months

Tuesday 28th July 2009
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Ye cannae put such cars in underground car parks.

Ditto channel tunnel.

LPG is cheap only as long as Winky allows it to be cheap.

Jem Thompson

930 posts

183 months

Tuesday 28th July 2009
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mybrainhurts said:
Ye cannae put such cars in underground car parks.

Ditto channel tunnel.

LPG is cheap only as long as Winky allows it to be cheap.
Why is that exactly?

Ed.

2,174 posts

239 months

Tuesday 28th July 2009
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Jem Thompson said:
mybrainhurts said:
Ye cannae put such cars in underground car parks.

Ditto channel tunnel.

LPG is cheap only as long as Winky allows it to be cheap.
Why is that exactly?
The duty is reduced on LPG only as long as it is politically favourable (reduced C02 etc) saying that last I heard it should not increase for the next 3 years.

Google [bot]

6,682 posts

182 months

Tuesday 28th July 2009
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My mate used to have a C36 AMG on dual fuel. Which was fine, when it wasn't exploding with such force it was smashing the airbox to pieces. Which it did often. Possibly a poor install, I don't know much about it apart from jumping out of my skin and then freezing by the side of the road.

JumboBeef

3,772 posts

178 months

Tuesday 28th July 2009
quotequote all
kjmac said:
Overall I reckon that LPG works out at 2/3 the price of petrol.
I find it is about 1/2 the price. LPG is normally less than half the price of petrol (currently 47ppl around here, and petrol is at 102ppl) and with LPG doing slightly less mpg than petrol, it works out to roughtly half the running costs (for me, anyway).

mybrainhurts said:
Ed. said:
Jem Thompson said:
LPG is cheap only as long as Winky allows it to be cheap.
Why is that exactly?
The duty is reduced on LPG only as long as it is politically favourable (reduced C02 etc) saying that last I heard it should not increase for the next 3 years.
A rolling three years, so you'll always have at least three years cheap motoring. It has been like that for a long time, and there is no reason why they would put it up any time soon.



Edited by JumboBeef on Tuesday 28th July 08:17

Silver940

3,961 posts

228 months

Tuesday 28th July 2009
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mybrainhurts said:
Ye cannae put such cars in underground car parks.

Ditto channel tunnel.

LPG is cheap only as long as Winky allows it to be cheap.
Never heard the underground car park thing?

Channel Tunnel because noone is willing to pay the huge cost for the safety accreditation.

Winky has said that duty on LPG will rise by 1 compared to petrol but they'll be no significant change for some time.

some random website said:
The government is clear on its support of LPG, through both financial and non-monetary means.

Primarily, the government endorses the use of LPG through perceived rates of taxation, guaranteed through the 'Alternative Fuels Framework'. The framework sets out:

•3-year, rolling programme whereby any change of duty must be announced 3 years before its implementation

•Guarantee that the current difference in tax between LPG and petrol (the 'duty differential') can change by only 1 penny per year for at least the next 3 years

Essentially, the Alternative Fuels Framework means that the 'half price' nature of LPG is virtually guaranteed for 3 years from every day that there is not an announcement from the government.

As a domestically produced product, the government has and will continue to support the increased use of LPG. It should be noted that the Queen, Prime Minister and Deputy Prime Minister all use LPG fuelled cars.

JRM Rossi

702 posts

190 months

Tuesday 28th July 2009
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Hi everyone i have run my dodge ram on lpg for just over 3 years now,runs 100% no problems so far
I used to have a 7.5 tonne tow truck then the london low emmision zone started!
Hence the ram on lpg

Matt UK

17,757 posts

201 months

Tuesday 28th July 2009
quotequote all
Silver940 said:
Never heard the underground car park thing?
I think it's because the gas is heavier than air nad hence 'collects' at low points

Matt_N

8,905 posts

203 months

Tuesday 28th July 2009
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Google [bot] said:
My mate used to have a C36 AMG on dual fuel. Which was fine, when it wasn't exploding with such force it was smashing the airbox to pieces. Which it did often. Possibly a poor install, I don't know much about it apart from jumping out of my skin and then freezing by the side of the road.
My mate also blew his inlet manifold to pieces on his 406 whilst using LPG, he did DIY the install though.

Matt UK

17,757 posts

201 months

Tuesday 28th July 2009
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I've looked into LPG on a few forums for my BMW and have decided not to go ahead with it.

The reason for me was that there were simply too many cases of bad systems / installs. I know it's all about getting the right system and the right installer, but for me it just seemed too hit and miss. Whenever you speak with an installer he'll say that him and his system are the best thing since sliced bread.

Then you read about systems having to be un-installed because they don't work properly. Plus my Indy said that all he ever sees with LPG cars is problems. Plus you need each year to get your car serviced and then your LPG system serviced seperately. Splitting routine servicing is a hassle - plus I read about situations where a car running dog-rough: LPG supplier blamed the car, mechanic blamed the LPG system, customer is stuck between a rock and a hard place.

Basically, there are so many options out there that I realised I would have to become an LPG expert myself in order to ensure I was having the right level of conversations with people in the trade. Each job is almost bespoke in it's application and installers preferences vary quite a lot it seems. And for that reason I got bored - I don't really have the time or desire to be an LPG expert. And I don't trust anyone do just "leave it to us". And a few hundred quid a year saving (once you've got back your £2,000 costs) doesn't interest me enough to take the risk.

On top of that, if Winky puts the price up then whole project is a waste.

I'll keep an eye on LPG as I like the idea of cheaper running costs, but for now I'll stick to Shell V-Power. I know where I am with that.

One final downside is that your car will smell like a forklift truck.

Jem Thompson

930 posts

183 months

Tuesday 28th July 2009
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All the taxis here in NZ use LPG (all the Holden Commodores/Ford Falcons), as well as some Holden police and government cars. If done well it should be reliable.

Zagadkateg

30 posts

194 months

Tuesday 28th July 2009
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You will smell the funny LPG odour - for about a second and a half after refuelling - less if there's a breeze! If you can smell it inside something is very wrong and my car isn't even watertight much less insulated enough to hide such things.

I do however take Matt's point about never really knowing what you're buying but really that goes for every used car bought or service most of us pay for.

My LPG install has been trouble free, paid for itself months ago and gives me at least an extra 150miles unrefuelled range when on a decent length journey.

Kev

(edit - typo)

Edited by Zagadkateg on Tuesday 28th July 10:21

Silver940

3,961 posts

228 months

Tuesday 28th July 2009
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Had my car done nearly 2 years ago. It was tweaked at 3k miles and serviced at 20k. Overdue for LPG service now. Done 50k miles since installed, car done 168k miles now, no real issues. It can hesitate a little in really cold weather at full throttle over 1 lepton, other than that no problems just cheap motoring.

Doesn't smell either, if it does something is wrong.

Only downside is the cheap motoring means you kind of tie yourself to the car, hard to justify changing it at the moment.

wolf1

3,081 posts

251 months

Tuesday 28th July 2009
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The only problems I see from LPG systems are when they are neglected as too many people see them as a fit and forget installation. Multipoint systems are the way to go as the old single point systems had too many problems (Backfiring into airbox and then promptly setting fire to under bonnet area in some cases). Yes parts are going to break just like the rest of the cars fuel system but it's not exactly hard to find an lpg specialist for servicing and repair work. Most garages declare LPG systems as unreliable because whenever they have tinkered it didn't work as they didn't know what they were doing, hence the 'Nah mate you don't want one of those lpg jobbies they're unreliable and expensive' from your local small garage.
Anyway if the system does stop working you have a perfectly good manufacturer fitted fuel system to allow you to drive to get it fixed smile

Carpie

1,118 posts

196 months

Tuesday 28th July 2009
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My old man had a V8 P38 Rangey a while ago which he had converted to LPG (or it may have been fitted when he bought it, either way it had been properly fitted, not a DIY).

It blew two head gaskets in the time we had it, which he attributed to the LPG, I can't remember the specifics of it.

I'd still buy a car with it, but I'd be wary of paying to have it fitted, and if I did I'd only use a well known and respected fitter.