LPG Conversion on your E30? If so - Pros and Cons

[davidorme591]

Hi everyone. LPG conversion on your BMW - Have you had your car LPG converted.. Can you recommend your conversion and why? I can vouch for my E34 525i Touring, has a BRC system - runs really well on LPG. I am looking at having my E30 converted too... your views would be appreciated ...Cheers David

[Brianmoooore]

I too have an E34 2.5 running a BRC system, and the only problem with that is that I can't get into the system with a laptop to adjust/check it.
I've also been running an E30 325 touring for about ten years/100,000 miles on a single point AEB Leonardo controlled system.
When I can find the time, I will also have a 1.8 touring running on a similar system, a M52B28 engined E30 touring on a multipoint vapour injection, and possibly a 325 cab on the stuff as well.
Pros: Cheap motoring, greatly extended range if you use both fuels (about 1500 miles on my E34 when I bought it!), increased engine oil life, greatly reduced engine wear, especially on cold starts, breakdown insurance in the form of having two completely independent fuel systems on board, feeling of smugness when you watch others filling their cars with fuel at around £1 a litre.
Cons: Loss of boot space and/or spare wheel., the need to locate an extra fuel filler somewhere, not being allowed to use some underground car parks or the cross channel tunnel, reduced choice of insurance companies.

[davidorme591]

The guy who fitted my system accesses the setup via laptop! My 525i uses a vapour system multi point too. It starts on petrol and very soon switches over.. The reason I asked about the other system is I cannot really convince my good lady to fit another £2000 system due to lower mileage covered on the 320i and the iX (collect it on Tuesday), so knowing of a reliable cheaper alternative would be good. The engine oil on the E34 its so clean even when it is due change.

[A1BMW325iSport]

not being allowed to use some underground car parks or the cross channel tunnel

didn't know that, cheers for the info

[Ilkorin]

Running a 325 on LPG right now, Brian has pretty much covered all the pros and cons...

Would definitely recommend doing the conversion mainly for the cheaper fuel - the system isn't too difficult to install yourself (unless you're a spade like me and can't work out how to bend copper pipe )... you will need a closed loop system though, and that will involve welding a lambda boss onto the exhaust. Obviously the effort involved means the system can probably be self-installed a lot cheaper than £2k...

[e301988325i]

Costs about £500-£600 to install a single point system yourself with new parts, one thing that hasn't been mentioned is the significant extra weight in the boot, my 60L tank weighs about 35kg dry.

[davidorme591]

The tank does replace the spare, however, Its the price we like, no good if you use the car for racing and weight is an issue I suppose.. Question: How many owners have LPG conversion.. add your name to the list.. name your car and system, self install or pro', cost Thanks for any info

1. Davidorme591 E34 525i tourer - BRC system - pro install £2k

[stonesie]

1. Davidorme591 E34 525i tourer - BRC system - pro install £2k
2. Stonesie E30 320 touring - BRC/OMVL/Leonardo DIY with Ebay bits and a brand new Leonardo £350

[Ilkorin]

1. Davidorme591 E34 525i tourer - BRC system - pro install £2k
2. Stonesie E30 320 touring - BRC/OMVL/Leonardo DIY with Ebay bits and a brand new Leonardo £350
3. Ilkorin E30 325i touring - Landi Renso (basically a leonardo), installed by previous owner (£??) + upgrade to toroidal tank (~£100)

we could make an LPG register....

[StuBeeDoo]

1. Davidorme591 E34 525i tourer - BRC system - pro install £2k
2. Stonesie E30 320 touring - BRC/OMVL/Leonardo DIY with Ebay bits and a brand new Leonardo £350
3. Ilkorin E30 325i touring - Landi Renso (basically a leonardo), installed by previous owner (£??) + upgrade to toroidal tank (~£100)
4. StuBeeDoo - 320i 2.7 Touring. DIY install - OMVL, Leonardo and 53ltr tank in spare wheel well. Total cost £700 (all new parts).

[e301988325i]

1. Davidorme591 E34 525i tourer - BRC system - pro install £2k
2. Stonesie E30 320 touring - BRC/OMVL/Leonardo DIY with Ebay bits and a brand new Leonardo £350
3. Ilkorin E30 325i touring - Landi Renso (basically a leonardo), installed by previous owner (£??) + upgrade to toroidal tank (~£100)
4. E301988325i - M20 B25, Leonardo AEB175, OMVL R90E, 60L doughnut tank, polyflex tubing, installed myself £500-600 all new except leonardo computer.

[Brianmoooore]

one thing that hasn't been mentioned is the significant extra weight in the boot, my 60L tank weighs about 35kg dry.

Not quite as bad as it seems - petrol tank + pump + 60 litres of petrol = 55kg.
LPG tank + 60 litres of LPG = 65kg.
I know that normally you will still have the petrol tank fitted, and still have some fuel in it, but there's nothing to stop you removing the petrol system completely if you want.

[stonesie]

+ the removal of the spare, not the lightest of things. At a rough guess i think my spare is about 15Kg and is now only carried on long journeys.

[davidorme591]

Keep adding the names... how many still out there... just filled up tonight 49.9p a litre Happpy. How do we keep this going Brian?

[Joshy]

Does running on LPG provide a noticeable drop in performance, I.E can you tell the difference when running on petrol and then switching to LPG?

[Brianmoooore]

Does running on LPG provide a noticeable drop in performance, I.E can you tell the difference when running on petrol and then switching to LPG?

If you modify your engine to optimise its running on LPG at the expense of petrol, then it should produce considerably more power, mainly as a result of LPG's increased octane rating, allowing you to run a higher compression ratio.
In the real world, with the engine still optimised for petrol, there will be a slight, but unnoticeable drop in power for a single point system, and there shouldn't be any difference at all with an injection system.
If the petrol system wasn't running at its best, you might still get a power gain, of course.

[gareth]

1. Davidorme591 E34 525i tourer - BRC system - pro install £2k
2. Stonesie E30 320 touring - BRC/OMVL/Leonardo DIY with Ebay bits and a brand new Leonardo £350
3. Ilkorin E30 325i touring - Landi Renso (basically a leonardo), installed by previous owner (£??) + upgrade to toroidal tank (~£100)
4. StuBeeDoo - 320i 2.7 Touring. DIY install - OMVL, Leonardo and 53ltr tank in spare wheel well. Total cost £700 (all new parts).
5. E301988325i - M20 B25, Leonardo AEB175, OMVL R90E, 60L doughnut tank, polyflex tubing, installed myself £500-600 all new except leonardo computer.
6. Gareth - M30 B35, AEB leonardo(used), OMVL R90E(new), donut tank(new) installed myself. £400 - 500 ish

[johnl320]

--------------------------------------------------------------------------------
1. Davidorme591 E34 525i tourer - BRC system - pro install £2k
2. Stonesie E30 320 touring - BRC/OMVL/Leonardo DIY with Ebay bits and a brand new Leonardo £350
3. Ilkorin E30 325i touring - Landi Renso (basically a leonardo), installed by previous owner (£??) + upgrade to toroidal tank (~£100)
4. StuBeeDoo - 320i 2.7 Touring. DIY install - OMVL, Leonardo and 53ltr tank in spare wheel well. Total cost £700 (all new parts).
5. E301988325i - M20 B25, Leonardo AEB175, OMVL R90E, 60L doughnut tank, polyflex tubing, installed myself £500-600 all new except leonardo computer.
6. Gareth - M30 B35, AEB leonardo(used), OMVL R90E(new), donut tank(new) installed myself. £400 - 500 ish

7. Johnl320- 1990 318is installed by jon_bmw, still going great guns

[Ilkorin]

I can just about feel the slight power drop at lower rpm, but I'm usually too busy feeling smug that my fuel cost has just halved! :p

[Brianmoooore]

There's no inherent reason why LPG should give less power at low RPM. I suspect this is a set up or system design problem, although solving it could well affect top end power.

[Grrrmachine]

Cons: getting a car with LPG fitted and being very hesitant about how to go about changing the air filter...

(the LPG throttle flap, or whatever it is, seems to be mounted above the air filter, making it awkward to go about servicing without disconnecting a lot of stuff I'm not quite sure I understand)

[davidorme591]

Great that the list is growing.. I am hoping to speak to the guy who fitted my LPG system soon. If I can help by putting any of E30 zone members in touch to throw more light on LPG setting up problems.. The guy I use is located at Antons Gowt (great name for a village) nr Boston, is very knowledgeable and use a laptop to interface whilst on the move to setup and monitor. Concerning the LPG itself, I try and use Shell LPG when I can get it. Has anyone found using supermarket or other LPG source cause running problems... Keep adding to the list guys

[stonesie]

Cons: getting a car with LPG fitted and being very hesitant about how to go about changing the air filter...

(the LPG throttle flap, or whatever it is, seems to be mounted above the air filter, making it awkward to go about servicing without disconnecting a lot of stuff I'm not quite sure I understand)

Can't you just disconnect the pipe to the mixer in the airbox? mine is in there too and being a strange twin pipe thing it was an arse to fit there but dosen't even need disconnecting to slip the old filter out and a new one in

[Grrrmachine]

there's valves and stuff all over the place, so I should be able to disconnect something to get it done. I've only had the car for 5 days, so it might make sense to take a photo and document it all so that other LPG users have an idea of the varients available on the market. I have no idea if Euro setups differ in practicality to UK installs (even though the theory is the same.)

It's a 32l tank in the boot with a single-point mixer, and the vapouriser behind the drivers headlight (on a LHD car), so NOT under the power steering reservoir as has been proposed by others (Mr Moore, I believe.)

[stonesie]

Thats a small tank,maybe 100 miles range? I dunno if the regs are different in poland but here they can only fill to 80% (IE i've never got more than 40L in my 52L tank)

[Grrrmachine]

yeah, 80% here too. Not drained the tank because the fuel pump is knackered so I cant switch to petrol, but I got 150km out of 27l, which is pretty much 100 miles and the tank close to vapours. Sits in the boot snugly though, with the filler nozzle mounted inside the tailgate just behind the light cluster. It's just about enough for my inner-city stuff though, and I'll have the petrol for distance cruising.

[davidorme591]

Any other zoners with LPG fitted? Please continue to put your names down David