LPG Conversion

[k6nwl]

Has anyone converted their merc to LPG. If so are there any performance/other/cost issues? Looking at converting my CLK 320 pertrol.

 

[bennesspipers]

IMO,its a bad idea,if it aint a factory fit from new dont touch it. Seen a large amount of cars that have had it fitted as an afterthought,they never work right & usually end up trying to sell em on (often worded as 'engine needs servicing' or 'tickover needs sorting') Usually its warped the cylinder head !! Also it turns your car into a potential bomb. Some of the fitting companies have a lot of unhappy customers !

 

[kth286]

IMO,its a bad idea,if it aint a factory fit from new dont touch it. Seen a large amount of cars that have had it fitted as an afterthought,they never work right & usually end up trying to sell em on (often worded as 'engine needs servicing' or 'tickover needs sorting') Usually its warped the cylinder head !! Also it turns your car into a potential bomb. Some of the fitting companies have a lot of unhappy customers !

I think you need to back that up with some facts and examples.

 

[bennesspipers]

A very easy way to do that is to read some car ads on e-bay, the cars listed as spares/ repair would be a good place to start, 'LPG removed' is quite common on there. Also, years ago a firm i was working for bought lpg kits from Calor to fit petrol engines,the whole job was an expensive disaster, & EVERY engine had to be converted back, some having to have new cylinder heads. Calor didnt want to know, & were no help at all !!!

 

[HumberMart]

It's not something I would do.

I worked at BG for many years, and was responsible for installing LPG filling stations at all their depots in the NE. At the time BG converted all their vans to run on LPG, and I drove quite a few. Power was always lower on gas, and as already mentioned, cylinder head problems became a big issue. Theoretical mpg on LPG was never acheived.

I also bought a boat once with twin BMW petrol engines that had been converted to run on LPG, but the previous owner had removed the LPG conversion in order to sell it. I tracked him down on the YBW Forum, and he said the conversion had been a total waste. It never ran well, power much less than petrol, lots of space lost to the equipment, and LPG in boats is a big risk. Less so in cars, but it's not something I'd be fond of in my car - and I'm a gas engineer!!

 

[mark_le_b]

Thats interesting info., because I was thinking of buying an ML500 that has had an LPG conversion........mainly because of the MPG advantages.

This gain in MPG may be a myth if you have to rev the car all the harder to get it to perform as well as on petrol then..........plus it souds like reliabilty is problem too!

Mark

 

[HumberMart]

Burned valves was another problem, the LPG (being a lighter hydrocarbon) does not provide the same level of lubrication that petrol does, and in fact can help defeat the lubricating effects of the engine oil. - still you won't need to decoke as often!

 

[Roger Jones]

I would have thought that LPG has been around long enough now to demonstrate that it is not an attractive option. I know that some who did consider it decided to hold off in the expectation that the duty would increase significantly if it ever caught on. It would certainly be a turn-off in any car that otherwise attracted me. And has any car manufacturer ever offered an LPG model?

 

[mark_le_b]

I think Mitsubishi had factory LPG option on Outlander model

 

[bennesspipers]

Yes Roger, Vauxhall for one

 

[k6nwl]

I Guess at the cost of conversion at around £1500 its not worth taking the risk, would be interesting to hear for any merc owners who have had one done.

 

[kth286]

Mercedes themselves actually make and sell gas cars into LHD and RHD markets.

Germany and Holland and Singapore for example.

The modern multi-point processor controlled systems are a world away from the old single point systems that backfired and blew the intake system apart.

There have been many posts on the various Merc forums from happy users.

 

[HumberMart]

Mercedes themselves actually make and sell gas cars into LHD and RHD markets.

Germany and Holland and Singapore for example.

The modern multi-point processor controlled systems are a world away from the old single point systems that backfired and blew the intake system apart.

There have been many posts on the various Merc forums from happy users.

Good points, all the issues I have related refer to adding LPG to old technology not designed for it. It is very different when the unit has been designed by the manufacturer to be duel fuel capable.

 

[Nibbo]

Well the local taxi company I use run all Mercs. They have two E Class, one S Class and even an ML.
ALL of them have been converted to run on both petrol and LPG and he swears by it.
No loss of power no engine problems and it paid for itself in months.
He switched between petrol and LPG whilst I was in the S Class and I could not tell the difference.
Obviously they do an enormous amount of miles so the return on their investment was relatively short compared to 'normal' use.

 

[stevieb15]

I would have thought that LPG has been around long enough now to demonstrate that it is not an attractive option. I know that some who did consider it decided to hold off in the expectation that the duty would increase significantly if it ever caught on. It would certainly be a turn-off in any car that otherwise attracted me. And has any car manufacturer ever offered an LPG model?

S80 Volvos I believe as apartof a dual fuel system

 

[k6nwl]

hmmm...interesting comments - more homework required I think

 

[HumberMart]

Copy from carkeys.co.uk...........(whilst comparing the success of some LPG conversions)

Some To Watch Out For
The same is not necessarily true of other manufacturers. For example, although the Jeep six-cylinder engine seems to accept LPG without any trouble, we know of a Cherokee V8 which has caused one reputable conversion company endless trouble. The Ford Focus, Nissan Primera, Honda CR-V, some Peugeots and any Toyota using lean-burn fuel technology have also been known to suffer valve problems.
Where these cars are available with factory-fit conversions (as some of them are), it's reasonable to assume that special cylinder heads with stronger-than-standard valve seats have been used. These may be next to impossible for a private buyer to locate.

 

[HumberMart]

Another web quote......
What effect does LPG have on economy and power?

Because LPG does not contain the same amount of energy as petrol, both fuel consumption and power will suffer. However, later model vehicles are generally less affected.
An increase in fuel consumption of around 30% to 40% should be expected when operating on LPG but this is offset by the lower cost per litre of gas.

 

[V12]

My dad went LPG crazy a few years ago, his list of LPG powered cars is well over 10 in the past few years, only 3 of which have operated correctly on LPG. The benefits really don't outweight the negatives and you will likely never make back the cost of installing the kit in the first place unless you commute 100 miles a day in a 6.0 V12. Somehoe he doesn't seem to be able to see this logically!

When his 2002 S500 runs correctly (usually only when it's warm-not often in the UK) it works out about the same pence per mile as my E320cdi. But once the S500 is running on LPG it can't quite keep pace with the mighty 320cdi...Switch it to petrol and the S500 will leave the 320 for dust at motorway speeds.
He also has a 1998 E430 estate which was previously a demo vehicle for the then top of the range LPG kit, i must admit this one doesn't drive too badly on lpg, but, being a demo vehicle for a LPG installer, the install work is of a much higher standard than any of the other conversions i've seen!

If you want economy, drive a diesel, if you want a petrol, get used to high fuel costs...

 

[bennesspipers]

My dad went LPG crazy a few years ago, his list of LPG powered cars is well over 10 in the past few years, only 3 of which have operated correctly on LPG. The benefits really don't outweight the negatives and you will likely never make back the cost of installing the kit in the first place unless you commute 100 miles a day in a 6.0 V12.

If you want economy, drive a diesel, if you want a petrol, get used to high fuel costs...

I agree with you wholeheartedly