LPG conversion- anyone done one? is it worth it?

[jimbo23]

Hi, I'm the proud owner of a 1989 300e, my first Merc & I love it, it's had a full service (1st one recorded in 5 years & only needed new brake pads ...the gamble paid off) ....any way back to the point as you know the fuel consumption on the 300e is not too bad but not to clever, I'm getting around 22 - 25mpg, I wondered about a LPG conversion.

Has anyone done one?, any good? is it worth it etc etc.

My main reason behind looking at is is I'm going to be towing a caravan so the mpg will be hit serverly.

 

[jberks]

There are 3 main problems with LPG in my view (plus I have something in the back of my mind about being banned from some tunnels butr not sure on that one)
so
1) Some installations go badly wrong and the car runs badly. Not a big issue, you just need to ensure you use a good installer.
2) Cost : I was quoted around £2k for an installation on an E240. Yes, you do save on the LPG, but it will take several years to recoup your investment. Remember, it isn't a 1l / 1l comparison. MPG drops on LPG so your 22-25 will probably be around 18. I was looking at >30k miles before I broke even.

3) Tank : I only considered a spare wheel tank as anything else destroys the boot space. The range on such a tank isn't that impressive. With the only LPG supplier in the wrong direction from my way home and not supplying petrol I would be filling 3 times a week on LPG + another once or so in petrol.

None of these are reasons not to do it, but its not the no brainer it first appears.

 

[Blobcat]

Hi jberks it is Euro-Tunnel that do not allow LPG tanks. Mont Blanc tunnel allow them which is what caused the fire a couple of years ago.
The systems fitted in the UK have extra safeguards compared to our european cousins conversions so should be safer.
Police force I used to deal with tried LPG on a traffic Volvo and five 2Ltr twin cam Transit dog vans. Every single one of them melted the pistons.

 

[996jimbo]

Hi jberks it is Euro-Tunnel that do not allow LPG tanks. Mont Blanc tunnel allow them which is what caused the fire a couple of years ago.
The systems fitted in the UK have extra safeguards compared to our european cousins conversions so should be safer.
Police force I used to deal with tried LPG on a traffic Volvo and five 2Ltr twin cam Transit dog vans. Every single one of them melted the pistons.

100% failure rate surely suggests a major cock-up with the installation?

I had LPG on my Range Rover and my only complaint was the tank range, but then it was a Range Rover. The biggest doughnut tank I could get was (I think) 90 litres which allowed about 70L max fill and would give a range of about 200 miles at about 13 mpg (on gas). On your car that would translate to about 250 - 300 ish mile range.

The main point though as jberks said above is that it will take in the region of 30,000 miles to recoup the cost assuming LPG remains half the cost of petrol. So you'll have to consider how many more than 30,000 miles you'll do in your 17 year old car and over what sort of timescale.

Personally I'd be quite happy to have another LPG car, but am not going to convert my AMG 'cause I've never heard of anyone having done one before. LPG does burn hotter and I'm not sure whether the tune it has leaves enough margin for error.

 

[Blobcat]

100% failure rate surely suggests a major cock-up with the installation?

You would think that the company would ensured they were good installations as there was the possibility of selling 500+ conversions. I'm sure that the drivers were testing the vehicles thoroughly. I understand the problems were because of the LPG burning hotter than petrol, this caused the pistons to melt.
I did not echo what jberks had written however I agree that the cost of the installation compared to the saving is the biggest issue. However if your engine is also likely to melt that would be a show stopper for me.
Friend with a LPG Jeep Cherokee found it very hard to set a clean idle on LPG.

 

[fwb44]

it is Euro-Tunnel that do not allow LPG tanks

To be pedantically accurate Eurotunnel don't allow filled LPG tanks - they must be empty (though I don't know what checks are carried out to establish this). LPG is so common in various European countries, as well as Japan, Southern California and parts of S. America - it's a shame it hasn't really caught on here. The best LPG fitter I know of is Gastech in Huntingdon who did two Volvo V70s and a VW Caravelle for us and take endless trouble to get it right - but herein lies the caveat - LPG conversion isn't trouble-free - the technology isn't very sophisticated - and M-B don't support it

 

[comfort zone]

Police force I used to deal with tried LPG on a traffic Volvo and five 2Ltr twin cam Transit dog vans. Every single one of them melted the pistons.

As a retired officer I can understand how that happened. Police right boots have extra lead fitted.

 

[Flying Scot]

lumpy idling seems to be ignition related LPG needs a much better spark than petrol so your HT leads and other HT bits need to be in top notch condition or you will get lots of problems.

I would love to convert the SL but scared that i would turn a sweet silky smooth running dream of an engine in a lumpy cantankerous horrible power unit.

still to find someone who can really say go do it and who will back that up with 100% support and meet my RR standards of installation subsequent performance and support.

 

[cubicincubi]

it isnt worth it. you wont recoup unless you buy a second hand kit and DIY fit then get it set up at a LPG service garage or buy parts and DIY fit.

I was lucky to buy one already converted and i paid about £400 over the list price for the car for the fact it had the kit.

£40 a week petrol costs in our previous V6 2ltr Mazda now come in at a tenner in the old faithful hack.

As far as reliability is concerned, mercs seem to do well on LPG. The E200 has covered about 60-70K on lpg without major hitches other than requiring two new fuel pumps as previous owner ran them dry.

You have to use your own judgement whilst running lpg and asess the thermal efficiency etc. Most horror stories on LPG are down to either poor user judgement with use, a bad install or sheer application incompatibility for the vehicle.

 

[citroennut]

lpg

hi jimbo, i bought an e240 2.5 years ago and just after buying it discovered how bad fuel consumption was! decided to convert to lpg, admitedly there was an £800 grant but installation was £2300. there was no difference in consumption 22mpg or performance and in fact the car idles smoother - no fluctuation in rev counter. i've had one problem in that time and it was the vapouriser was badly manufactured inasmuch as the water pipes were too close to the gas pipes and perforated which pressurised the cooling system. dealer spent 27hrs looking for problem inc taking the heads off! i would like to state publically how good the garage was during all this and only charged me for 1hr labour! all dealers are not the same! new vapouriser now takes longer to heat gas and fuel consumption down to 19mpg - as to whether to convert or not
1 how far nearest filling station
2 how long do you intend to keep it
3 how many miles will you tow
obviously 2&3 combine and the poorer the fuel consumption the sooner the cost recouped. always go for a multipoint injection system far better there may even be one specifically for that engine
simon

 

[robbi-wan]

hi Jimbo,
Mine is diesel and there is not yet a LPG system available for it (although they are apparently being developed), anyway: i sometimes wish i had converted a petrol something or other for a couple of reasons, money and money.
A mate of mine in a band used to have a 4l Jeep on LPG and towed with it and also did around 500 miles/week on £18!!
You can also get your petrol tank modded for extra space in addition to the toroidal (spare wheel) tank, it will increase the payback time but could get around the "Bootspace vs Extra LPG Tank" dilemma.
If you do enough miles to justify the expense, the savings could be significant.
You are perfectly entitled to ask for certificates of competency etc when selecting an LPG system supplier and all have to supply an LPGA certificate of conformity for your insurers (who will want to know about the mod).
Check out http://www.lpga.co.uk/LPGA.htm these are the "CORGI" equivalent.
I sometimes have to drive past LPG stations on my way to work - and every time i see them i think of what i could have saved :sad:
If you do your research properly - you wont go wrong!
rob

 

[jimbo23]

wow - not had chance to check the forum since posting until now, thanks so much for all your replies.

Ok so .... mileage wise I'm going to be doing approx 18000 per annum, about 2000 of those would be towing, I have a 50 miles a day round trip commute to work each day.

As for how long I'm planning to keep the car, well the original idea was for a year but having said that I enjoy driving it so much that I can't see any reason why I would want to change it other than fuel costs, it drives beautifully, it's more than big enough for me the wife and sprog & is the most comfortable car I've ever driven.

So with that in mind I would say that I'm planning to keep it for as long as it keeps going or until I have the money to replace it with a newer version, but money wise that will be a few years from now for sure.

 

[diy_dan]

wow - not had chance to check the forum since posting until now, thanks so much for all your replies.

Ok so .... mileage wise I'm going to be doing approx 18000 per annum, about 2000 of those would be towing, I have a 50 miles a day round trip commute to work each day.

As for how long I'm planning to keep the car, well the original idea was for a year but having said that I enjoy driving it so much that I can't see any reason why I would want to change it other than fuel costs, it drives beautifully, it's more than big enough for me the wife and sprog & is the most comfortable car I've ever driven.

So with that in mind I would say that I'm planning to keep it for as long as it keeps going or until I have the money to replace it with a newer version, but money wise that will be a few years from now for sure.

Had a 190e which I converted and only had 1 blowback on it, This took out the air filter, I change the system to a sequential injection and it ran ok, I just got a 300ce which I converted and this give me 16mpg on lpg. I was hoping for 18-20 but yesterday was doing some calculation and found that petrol was 96ppl and lpg was 40ppl so with my flaky maths I would say I get 38 miles on lpg for the price of a gallon of petrol. beats diesel and is quieter. I never look at recoup period but if I did I would be talking 1 yr to 18 months. At 50 miles per day you would be talking £5 in lpg. Is that £10 in petrol? thats £25 per week save * 48 weeks = 1200 saved in a year

 

[fwb44]

My partner is just about to buy & LPG-convert a 2000 W210 E320 V6 Elegance estate which she reckons will give her the equivalent of 50 m.p.g. at petrol prices. She will be getting the work done at Gastech of Huntingdon who say this is "an ideal conversion" and like me she does 60K+ miles a year in the chauffeur business so it will soon pay for itself. But try to find a mechanic with a good word to say for LPG conversions! Without exception they've "never known one without problems" and so it's an article of faith whether you get it done - but for us there are very compelling economic arguments in favour of it

 

[robparker]

Had a 190e which I converted and only had 1 blowback on it, This took out the air filter, I change the system to a sequential injection and it ran ok, I just got a 300ce which I converted and this give me 16mpg on lpg. I was hoping for 18-20 but yesterday was doing some calculation and found that petrol was 96ppl and lpg was 40ppl so with my flaky maths I would say I get 38 miles on lpg for the price of a gallon of petrol. beats diesel and is quieter. I never look at recoup period but if I did I would be talking 1 yr to 18 months. At 50 miles per day you would be talking £5 in lpg. Is that £10 in petrol? thats £25 per week save * 48 weeks = 1200 saved in a year

16 mpg with a 300 ce? is that town driving? my 230ce gets 25mpg on LPG on the motorway, a 300 surely shouldnt be that much worse..???

 

[fwb44]

It's not what you drive, it's the way that you drive it...;-)