evo 6 lpg conversion...
evo 6 lpg conversion...
Author
Discussion

cra1gy1989

Original Poster:

293 posts

171 months

Tuesday 18th September 2012
quotequote all
Hi all,
Been looking at a few forums regarding this subject, and wondered what your thoughts are...

At the moment I'm spending £100 a week on fuel, with the lpg conversion it would half the cost! would it reduce bhp? Engine wear? anyone had this done?
Thanks

Tonberry

2,277 posts

219 months

Tuesday 18th September 2012
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Surely not wise on a turbocharged car. Especially something that will be run hard.

sodslaw

189 posts

166 months

Tuesday 18th September 2012
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The fuel might be half the price but it doesn't use half the fuel because the engine uses more LPG...

LuS1fer

43,417 posts

272 months

Tuesday 18th September 2012
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I believe that LPG has a lower energy value so you only get something like 85% of the mileage from petrol plus you have to fit an extra tank plus you pay more in the winter as it has to be heated by garages. I'm not sure whether a car requiring premium fuel can run on LPG as I think it's equivalent to something fairly low in octane.

christofmccracke

881 posts

227 months

Tuesday 18th September 2012
quotequote all
Few guys in the mlr have done ithttp://www.lancerregister.com/showthread.php?p=2054159
But is it worth spending nearly half the cars value on saving fuel ?

cra1gy1989

Original Poster:

293 posts

171 months

Tuesday 18th September 2012
quotequote all
LuS1fer said:
I believe that LPG has a lower energy value so you only get something like 85% of the mileage from petrol plus you have to fit an extra tank plus you pay more in the winter as it has to be heated by garages. I'm not sure whether a car requiring premium fuel can run on LPG as I think it's equivalent to something fairly low in octane.
I thought lpg was equivalent to 106ron? Or am I lieing?

Also if only gets 85% of mileage would I be correct in saying I would still save 35% on fuel?

cra1gy1989

Original Poster:

293 posts

171 months

Tuesday 18th September 2012
quotequote all
christofmccracke said:
Few guys in the mlr have done ithttp://www.lancerregister.com/showthread.php?p=2054159
But is it worth spending nearly half the cars value on saving fuel ?
I've had a quote of 1350 for the conversion, which I thought as reasonable, as I would spend that much on v power in 13 weeks?

LuS1fer

43,417 posts

272 months

Tuesday 18th September 2012
quotequote all
cra1gy1989 said:
I thought lpg was equivalent to 106ron? Or am I lieing?

Also if only gets 85% of mileage would I be correct in saying I would still save 35% on fuel?
You may well be right:
http://www.go-lpg.co.uk/whatislpg.html

Don't ask me maths questions, I'll just make up the answer.

kwak

210 posts

179 months

Tuesday 18th September 2012
quotequote all
cra1gy1989 said:
I thought lpg was equivalent to 106ron? Or am I lieing?

Also if only gets 85% of mileage would I be correct in saying I would still save 35% on fuel?
LPG does have a higher octane value, but that mainly indicates resistance to knocking, not energy content.
so a car on lpg will use more fuel for the same power. Although if I understand it correctly, you would be able to run higher turbo pressure or compression ratio before running into problems.

kambites

71,235 posts

248 months

Tuesday 18th September 2012
quotequote all
cra1gy1989 said:
Also if only gets 85% of mileage would I be correct in saying I would still save 35% on fuel?
41%, if it's half the price of petrol.

edward1

839 posts

293 months

Tuesday 18th September 2012
quotequote all
Whether it is worth paying for a conversion is a personal thing. I won't increase the resale value of your car (at least not on a performance vehicle) so you have to work out if you will save enough on fuel of the time you plan on keeping the car.

If you work it out based on loosing 20% from your petrol MPG figure then use you local petrol and LPG costs (in Sheffield it is 69.9p/l compared to around 140p/l) to estimate the cost per mile on LPG compared to petrol. Until this summer the LPG cost was slightly more than half the petrol price but petrol went up and LPG stayed about the same and LPG has been about 45% the price p/l of petrol until it went up last week.

Generally the less efficient your car the quicker you will break even from the conversion cost and start saving. As long as the converter knows what they are doing and have worked on that type of vehicle before (and can show evidence of it) you should be OK Forced induction cars can be converted. You may find with a blown 4 pot however the gas injector rating could be an issue but you converter should know.

kambites

71,235 posts

248 months

Tuesday 18th September 2012
quotequote all
Forced induction should be fine; directly injection will not work on 100% LPG. I assume the Evo isn't direct injection?

rob.e

2,863 posts

305 months

Tuesday 18th September 2012
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Chap on the skoda forums tried this on a vrs (2 litre petrol turbo) and could not make it work properly.

Buying a cheap snotter has to be the answer surely?

kambites

71,235 posts

248 months

Tuesday 18th September 2012
quotequote all
rob.e said:
Chap on the skoda forums tried this on a vrs (2 litre petrol turbo) and could not make it work properly.
I suspect that's be because it's direct injection.

edward1

839 posts

293 months

Tuesday 18th September 2012
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As far as I understand direct injection for LPG is still a dodgy area. I assume the evo isn't direct injection.

monthefish

20,467 posts

258 months

Tuesday 18th September 2012
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The numbers don't really stack up for LPG these days...

If a decent conversion costs £2500, and

LPG costs 75p/litre (£3.41/gallon)
Petrol costs 1.40/litre (£6.37/gallon)

The saving by using LPG is £2.96/gallon

You would have to use 845 gallons before you break even which is over 21,000 miles*

(* at 25mpg, which is probably the level you get from a car you would consider getting an LPG conversion performed on)

In fact, the breakeven point is probably even higher than that, as I understand that LPG isn't quite as efficient as petrol, litre for litre.

Plus, LPG isn't 'half-price'; depending on your local prices it will be around 60% of the petrol price per litre, but with LPG having a lower efficiency so the equivalency is probably only a 30% saving.

DanDC5

19,963 posts

194 months

Tuesday 18th September 2012
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Buy a cheap st diesel and use the evo at weekends.

anonymous-user

81 months

Tuesday 18th September 2012
quotequote all
Not sure it's ever been much different. Only ever convert a car if you're going to do a lot of miles, keep it for a long time, or both. Break even is inevitably longer than man maths suggests because of the lower calorific value of LPG and the way the price goes up in winter because of the demand for it as a heating fuel.

Also on a turbo engine you need to have an installer who really knows their stuff, especially if you're talking relatively big power from small capacity like an Evo. You do not want it starting to run lean at full chat because the gas system can't keep up. Finding a good installer you can trust is probably the hardest part of the whole process.

sparkyhx

4,200 posts

231 months

Tuesday 18th September 2012
quotequote all
monthefish said:
The numbers don't really stack up for LPG these days...

If a decent conversion costs £2500, and

LPG costs 75p/litre (£3.41/gallon)
Petrol costs 1.40/litre (£6.37/gallon)

The saving by using LPG is £2.96/gallon

You would have to use 845 gallons before you break even which is over 21,000 miles*

(* at 25mpg, which is probably the level you get from a car you would consider getting an LPG conversion performed on)

In fact, the breakeven point is probably even higher than that, as I understand that LPG isn't quite as efficient as petrol, litre for litre.

Plus, LPG isn't 'half-price'; depending on your local prices it will be around 60% of the petrol price per litre, but with LPG having a lower efficiency so the equivalency is probably only a 30% saving.
Lets start with facts
- Firstly an installation will not cost £2500 closer to £1200 for a 4 cyl engine more for 6/8/12 cyl
- I currently pay 60p per litre for LPG
- you will loose around 15% mpg, although a mate of mine says he loses nothing on his 3 cars. On both mine I loose about 15% - its hard to guess cos you never do a petrol journey again.
- some types of car can suffer from valve seat recession - mainly toyota, but there are others. Its not an issue, it just needs a little extra bit of installation - your installer should advise
- the less MPG your car does, the quicker the payback period (if your car averages 20mpg payback will be half as many miles as one that does 40mpg) - I kept detailed records and I reckon mine paid back within a year (around 18k miles on an LS430 with £1800 installation)
- resale values tend to be slightly higher

SUNDRY FACTS/DO's and Donts
- Do go to a decent installer - personally I would avoid all the 'do it in a day' people. My installer takes 3-4 days
- Do get a certificate (need this for insurance and car tax discount)
- Cos its classed as a modification some insurance companies rate it, others are sensible enough to realise it has no effect.
you cannot go thru Channel Tunnel
- Service it like any other car i.e. its an extra fuel system so filters need replacing - its not install and forget.
- I use these guys - they seem to know what they are doing. and have done evo's, porsche, BMW, Bentley etc
http://www.pioneergasltd.co.uk/ I have no affiliation with them


Edited by sparkyhx on Tuesday 18th September 15:19

monthefish

20,467 posts

258 months

Tuesday 18th September 2012
quotequote all
sparkyhx said:
Lets start with facts
Yes, let's.


sparkyhx said:
- Firstly an installation will not cost £2500 closer to £1200 for a 4 cyl engine more for 6/8/12 cyl
I'm sure some backstreet garage will do it for £1,200 (possibly even less) but you are unlikely to get a quality job for much less than £2k when you include the VAT.

Even if it was £1200 all in, that's still around 11,000 miles before any saving is made whatsoever, so you have to be sure you are keeping the car for the long-haul before you would consider this.

And we've not yet touched on the fact that nobody can/will guaratee LPG will remain at such low prices, but there's regular hints that it may increase dramatically, so it is very possible that the price could gradually rise, and you're forever chasing your payback.


sparkyhx said:
- I currently pay 60p per litre for LPG
So what? The standard price around the UK is currently 72p (and, as said above, no guarantee it will stay at these levels)




I am totally unbiassed on this as I was seriously considering this after hearing some other evangelical soul preaching about how good it was. When you actually crunch the numbers, however, it really doesn't stack up in the majority of cases.

But come on then, if you're so sure it's the way forward, let's have your figures.