LPG Conversions

I have had two sevens converted to LPG, the current one being my 1997 car. This has sequential gas injection, with two injectors each feeding via a special valve to three cylinders, and 6 and knocks spots off petrol. Performance is splendid, emissions almost zero - last time it was tested I left it on LPG and the guy thought that his emissions machine had died! Oil is cleaner and lasts longer.

Best part of it all is the cost. If you have your own tank, you can buy at around 27 pence a litre including all taxes. If you buy at the garage, the cost varies from around 32p Morrisons Supermarkets to 44p in Oban. Consumption is about 10-15% more than petrol, but it works out at around 1/3rd to 1/2 the cost of petrol.

Whatever you do, don''t purchase a single point injection system. It will likely backfire and blow out your air meter. Can be expensive.

If you need to know more about the system - log on to www.autogas.com or do a search for AG Autgas systems.

Thanks Howard, I am seriously considering converting to gas.  Have you had any problems getting the car serviced since converting them?  I heard a rumour that some garages wont touch LPG converted cars.  Do you know if main BMW dealers will work on them?

Thanks in advance 

In order to get insurance, you have to have a certificate to show that the car has been converted to gas by a professional converter, usually belonging to the LPG association. I have had no trouble with this at all.

It is also wise to take out an insurance policy if your car is still under warranty, to cover parts that are invalidated due to them being modified during conversion. In my case this cost £300 and lasted for three years. I have not had to use it, so it was a waste of time.

When my 728 engine died at 53K miles due to a cylinder lining problem, (caused by high sulphur petrol used by the previous owner) the BMW agent from whom I had bought the car, refused to replace the engine until I had had the gas pipes disconnected from the engine by an LPG company. Luckily there was one down the street, and he took them off, and replaced them after the new engine was installed. The reason for this was that the BMW guys had no one who understood the LPG system, and were afraid that they might be called upon to pay for any damage to it caused by their working on the engine.

Some underground car parks will not let you in if you have LPG installed. They also do not let you in if you have a camping gas cylinder in the car! This is because LPG is heavier than air, and tends to pool on the floor. Presumeably this is why they won't let you on Le Shuttle. Why would any self respecting Englishman use Le Shuttle anyway. Personally I never go anywher near France!

My car has been service at the BMW agent where I purchased it, and at Almondbury BMW in Huddersfield from new. No one has refused to work on it. The mechanic will sometimes put a note on the service record saying that there is a slight smell of gas under the bonnet, which is true, but I now turn the gas off when leaving home and run on petrol until the service is done.

If you get an oxygen sensor failure, that is installed by your BMW Agent, do not run on LPG until you have taken your car to the LPG agent to reset the LPG system, and never allow your car to run out of gas while the engine is running, as damage to the oxygen sensor can result.

I have been associated with LPG driven cars since the early 1970s, when I used to supply Landi in Holland with tank brackets that were fitted on the Volvo assembly line. Over 1.5 million cars run on LPG in Holland. There are even a few LPG stations in Germanynow, though some of the use compressed natural gas. If some one tries to persuade you to use this system - run like mad. Its a dead item in this country.

The final question as to safety - its all down to hores for courses. A badly installed petrol sytem is worse than a properly installed LPG sytem.

BMW produced some LPG powered cars in the 90s for testing purposes. They have decided that Hydrogen is a more practical gas for use in cars though its explosive characteristics are much more dangerous than LPG.

How would you feel about driving around with half a ton of Hydrogen in your boot?

My experience with LPG is with the Ambulance service. Converted Ambulances ran nowhere as well on gas as on petrol.

• There is no way I would convert my E38 to LPG. I bought it for the space comfort & power. (power mainly)
• If petrol consumption was a concern I would have bought two Reliant Robins!
• It boils down to "Each to his own" I mean no offence to those who have had the conversion done.
• It's just not for me.
• At the moment the motor in my car is giving 300bhp !

Oh yes and LPG is availlable everywhere in france  even in supermarkets. Its also quite a lot cheeper than it is over here, about 0.4 euros which is 28 pence.

cheers

With regard to Colin.taylor9's comments on ambulances, I would agree. Most of them are converted using old systems with single point injection.

If his E38 is giving 300BHP on petrol then it is either a very good 740i (286 BHP standard) or a dog rough 750i (326 bhp standard).

Mine is a 738 (193BHP standard) As a pensioner on £450 a month, my 738 would have been pensioned off long ago if I was to run it on Petrol. Horses for courses.

On to connectors - James Gray - there is some variety in these, but I have travelled in Holland and Germany and the UK with my standard Euro connector and had no problems - apart from the scarcity in Germany, where they tend to use compressed natural gas. The connectors are standard in most Euro countries - including France. Additional connectors can be bought at around the £60 mark in the UK, but while I have one of each, I have never had to use them.