Low MPG on LPG Autogas car?

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Mon 17 Jul 2006 13:25
Low MPG on LPG Autogas car? - boxer99
Hi,

I am a new member to this forum but have been following it for a while.
I must commend you all on the mass of motoring knowledge you have.

I have an LPG converted car. The car is a 1984 B reg Audi Coupe 2.o Injection 5 Cylinder. When I bought the car it was already intalled with the LPG kit.
The problem is I only get around 140 miles (local miles) to 60 litres of gas. According to my calculations thats about 10mpg on LPG.
I assumed I would be getting about 250-300 miles at least on a tank of LPG.
Could any of you advise me as to what problems there could be?

Many Thanks

Boxer
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Mon 17 Jul 2006 13:29
Low MPG on LPG Autogas car? - Armitage Shanks {p}
Sorry to jump in here but, if the car is actually running OK on Autogas I might suspect a gas leak and I would be VERY frightenened. You don't say whether it is has always been bad on gas or if it is a recent problem.
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Mon 17 Jul 2006 13:35
Low MPG on LPG Autogas car? - boxer99
Hi,
It been like this ever since ive had it. Its been about 3 and half months.
Whenver I get inside the car I can smell gas. I tested so seei f there was a gas leak using one of those gas test meters I got on ebay for £20. The detector could not find gas anywhere in the interior, around the gas tank etc.
As this is the only LPG car I have owned...is it normal for LPG cars to smell slightly of gas, also if I stop anywhere for a few seconds and leave the car idling, and walk up behind the car, I can smell gas coming from the exhaust.
I know gas will come out the exhaust if its an LPG car but should the smell be so strong?
Is the MPG im getting on gas seem low or is that normal?

Thanks
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Mon 17 Jul 2006 13:39
Low MPG on LPG Autogas car? - Happy Blue!
Assuming that the car can run on petrol as well, why don't you run it on petrol only for a couple of weeks and compare the economy. If the petrol economy is only about 15mpg then you have a general economy issue. If the petrol consumption is at least 20mpg , then I would have thought that you have gas leak.

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Mon 17 Jul 2006 13:50
Low MPG on LPG Autogas car? - Armitage Shanks {p}
Following on from Espada's knowledgable post, here is another idea. Fill the autogas tank full, run the car on petrol for a week or two and then try and top up the gas tank. You haven't used any, so if you can get some in you have a leak, I'd say. Having read the horror stories of exploding houses, bungalows, blocks of flats etc I'd be very worried about the slightest smell of gas or petrol in a car. I hope you aren't a smoker BTW!
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Mon 17 Jul 2006 13:51
Low MPG on LPG Autogas car? - Armitage Shanks {p}
Further thought - if you can smell gas but a detector can't detect it what is wrong? Your nose or your cheapo detector?
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Mon 17 Jul 2006 13:56
Low MPG on LPG Autogas car? - boxer99
Excellent Idea,
Will definitely give it a try.
Im a non smoker....thankfully!!!!!

many thanks for all your suggestions.

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Mon 17 Jul 2006 16:01
Low MPG on LPG Autogas car? - Gromit {P}
BTW, you shouldn't be able to smell gas inside the car.

Its some time back, but a work colleague had a factory-fit LPG conversion in a new Opel Corsa. It was indistinguishable from the petrol equivalent - including no gas smell!

An easy way to test for gas leaks is to brush a weak solution of wash-up liquid onto the suspect joint - you'll see it bubble up if there's any leak. But don't take any chances - or park indoors, for that matter, until you're satisfied beyond doubt that all is well with your LPG installation.
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Tue 18 Jul 2006 11:35
Low MPG on LPG Autogas car? - expat
There should be no smell except when you are filling up. I use LPG cars from our work fleet often and there is no smell. Try posting on this site:
www.lpgforum.co.uk/
These guys should be well up on the whole thing.
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