Advice on autogas conversion

[Aidan Gillen]

In March this year I bought a very low mileage 1994 C180 auto from an elderly aunt. I cover about 40000 miles per year, so the economies which would be gained by spending the £1400 on a gas conversion would be helpful - I reckon the installation would pay for itself within 9 months.
Does anyone know of any problems associated with the conversion - It would be a pity to spend the money and end up with a beautiful car turned into a disaster area!

 

[Anonymous]

Yes - should be ok.
I had my 300e 1987 with 170k on the clock converted and it runs fine.
Few things to watch out for.
Extra weight and loss of space in the boot.
Loss of power (high rpm 5000 +), or when towing
Filling stations limited (although you can run on petrol)

Quirks with the system, ie after running on gas for 100 + miles, the fuel system de-pressurises, and when you start the car again, it takes some cranking to make it start.

Other than that it has already paid for itself.

 

[Aidan Gillen]

Thanks for the reassurance Russell - I am becoming more convinced as time progresses. The power loss wouldn't bother me too much - my merc usually cruises between 2000 and 3000 rpm. I hadn't considered the extra weight though - Does it affect the way the car handles in any way? Also the fuel de-pressurisation - Can this be overcome by starting on petrol and switching to gas when the engine starts? Another thought which has just hit me (I am a bit green round the ears when it comes to things technical) How do you know how much gas you have left?
allthebest

 

[Neil Eglintine]

One of my colleagues has a V12 BMW with gas. You can't tell the difference between gas and petrol. He has an LED fuel guage for gas level. Working on a cost basis, he gets the equivalent of 38mpg.

We are running a fleet of vans with lpg. Although we've had some problems with the tanks (repaired under warranty), the running characteristics of gas have been fine. The drivers like the vans, we like the costs

 

[RUSSELL WHEELER]

The car always starts on petrol, and as soon as it reaches 2000 rpm flicks over to gas.
The way I overcome the quirk of depressurising is to switch to petrol just before I stop the car (on long journeys)
You do get a fuel guage (bank of leds), and a more accurate guage in the boot.

The extra weight did make the back end sag a little (although I think the 15 year old springs may have more do do with it).
To compensate for this I have inserted some spring assisters (basically a rubber bung that fits in between the coil and stops the spring compressing)
I havn't noticed any change in the handling of the car with a gas conversion.

Last thing is that depending on the car will depend on the type of conversion.
My conversion on an older car works by feeding gas into the air intake, and switching off the fuel pump.

Later conversions inject liquid gas and integrate with the cars electronics more.
Be wary of cheap conversions, they will use the simpler system (even if your car needs a more complicated system)
see autogas2000.co.uk for registered installers.