Update

- LPG station list now available for GPS receivers.

What is LPG ?

It's liquid petroleum gas, a substance which occurs naturally and is a by-product of the petrol production process. You can run cars on it. It's very clean, has almost no emissions and will not contaminate your engine oil like petrol does (hence no sludge and less frequent oil changes). Also it is only 30-40p a litre.

What's the catch ?

You knew there had to be one didn't you ? It costs £1000 or more to convert a car to run on it. Sounds like a lot doesn't it ? It's probably more than my car is worth, but I'm getting it converted anyway. Take a look at this Excel spreadsheet and you will see why .. I can save enough money each month by running on LPG that I can pay for the cost of the conversion in about a year without it costing me a penny more. Of course I need to come up with over a thousand pounds in the first place, but thanks to Cahoot I have a credit card with 0% APR fixed for the first year. Tesco and several others offer very low fixed APR which are similarly useful for this purpose.

So who can convert it ?

Well there are a fair number of installers now, most are listed from the following sites - You can also install the system yourself, if you are confident in your ability to carry out the work to a high standard. Kits can be sourced for as little as £400 plus VAT depending on the vehicle and system required. I am currently installing my wifes car with LPG which I sourced as a kit from Gas Converters down the road from me in Caxton. Pages about the DIY install are just being built here. Following conversations with Gas Converters, and learning more about LPG systems I have to say I am less than pleased with the work which was originally carried out on my car. I am altering the majority of the system so that it will perform better and give better economy too (as well as being safer). More on that later ..

First Impressions

Wow ! I just got it back over the weekend, and what can I say ! I'm very impressed with the performance, I really can't tell the difference (it may be a little slower because my wallet is heavier - £21.50 to fill it up !). The installation is very neat, with the 60 litre (gas capacity, it automatically leaves 20% empty for expansion) tank fitting snugly into the spare wheel hole and sticking up about 6cm from the boot floor. When the carpet is back in you can tell that the floor is higher, but it still leaves me the length and ability to use the folding seat for maximum loadspace - I like it.

The filler is very neatly fitted where I asked it to be, and is almost un-noticeable (see picture). Under the bonnet it's very neat too, with the vaporiser just under the battery tray where it fits nicely since I already removed the big old airbox. The mixer into the throttle body and injector emulators are the only other additions and these take up hardly any room either. Inside the cabin the changeover switch is fitted in front of the drivers left knee on the fusebox cover panel, this seems like a good arrangement as this would be easy to replace should I ever decide to remove the gas system when selling the car or similar.

Pictures

The excellent loan car from Clean Air Vehicles. A 3.5 Litre V8 LWB Landrover automatic, running on LPG or Petrol. Great fun :)
Loaner

Location of the filler hole, very discreet
Filler cap

Vaporiser, fitted snugly under the air filter next to the battery tray.

Mixer (ringed in green) and injector emulators (ringed in cyan)
Mixer, ECU

Fitting of the tank, very neat - and all the pipes go straight out downwards so don't get in the way inside the boot at all.
Tank Fitting

Location of the switch pack inside the car -
Changeover Switch Changeover Switch

Additional Notes

This is mostly waiting for my photos to come back so I can scan them in. But in short I've removed the unecessary injector emulators, added a lambda probe to the front exhaust manifold, replaced the gas controller with an AEB Leonardo to give closed loop operation and dynamic mixture control. I've also just fitted a tank level sender, which only took 15 minutes to fit and is annoying that they didn't fit one in the first place. In addition I still have to fit an LPG isolation solenoid at the tank itself, as currently there is an LPG line under pressure going all the way under the car. It is protected by the flow-rate shutoff feature of the multi-valve, but it should have been fitted with a solenoid in the first place to comply with the COP11 guidelines. Overall I'm not very happy about the work carried out on my car, and I'd highly recommend talking in great detail to anyone who you are considering touching your own car. I really wish I'd installed this myself now ..


Installation of the Leonardo controller, note compared to picture above that this is where the injector emulators used to be located :) they are now going onto our second car. Conversion of this is being covered here. The controller is the box in the middle, and the stepper motor which controls the mixture is just to the left of that in the vapour hose. Click the image to enlarge it. Since fitting this my economy has risen from 19.7mpg over the last 7000 miles with open-loop to 21.7 over the 700 miles that I've been using closed loop control. Compared to the 26-27mpg that I used to get on petrol for the same type of driving that means I'm actually getting more than the 78% figure which the energy in the gas should limit it to. The benefits of closed-loop control are obvious from the figures, what is not obvious is that performance is now phenomenal ! I must get it on the computer again soon and do a 0-60, I'm prepared to bet it's within a few tenths of the best ever time on petrol :)

Links

  • DIY LPG kits purchased direct using secure online payments

    Note

    Since emptying my LPG tank completely on several occasions I have noticed that the amount required to refill it (always on a level surface) was varying (from 60 litres to 65). This prompted me to contact the local trading standards agency who informed me that they did not monitor the accuracy of LPG pumps, they don't have the equipment apparently. I'd like to know who's job it is exactly then ..