Essex LPG Autogas Conversions Ltd, Essex

I had Alan convert my wife's Xtrail and I was so impressed by the ease of use and the savings to be made that I then chose to convert my own car. That's 2 x £1600 and I consider it money well spent.

Alan (owner of www.essexlpg.net) operates from premises on a working farm in Stambridge, Essex SS4 2BF. He does employ one mechanic but otherwise it's a very small operation. Though small he has been LPGA accredited and has all the necessary equipment such as an exhaust gas analyser. If you do go there remember it's his work that counts not posh showrooms.

You leave your vehicle with him and pick it up usually a week later. He prefers to be paid by Cheque when you leave the car or Cash when you pick it up.

Externally there are few clues to your new fuel source. A small brass nozzle covered by a plastic cap is all the external sign that you're saving at least 40% on motoring. On the Xtrail it was at the back under the bumper but on my car he did cut a hole near the petrol filler. Either option is pretty unobtrusive. The usual tank placement is in the spare wheel location and thus your spare wheel is displaced. You can choose not to carry one -relying on tyre inflating puncture repair cans to get you home or as I choose to do carry the wheel in the boot. Under the bonnet there are a couple of extra boxes of electronics and a 'vapouriser' feeding new injectors set into your inlet manifold. I don't understand all the extra gubbins there but Alan does a really neat job fitting it all in. Your local dealer will still service your car as normal - mine did.

A note on safety. I'm told there are numerous safety features not the least of which is that the tank is considerably sturdier than a petrol tank and there are safety cut off valves that click in when the ignition is off. I'm no expert on this but I have used the kit for two months on two cars and it's been fine.

On the road. You start the engine on petrol and once it warms up it switches to gas. That's it. No input from you. There is a small postage stamp sized box on the dash that has LED's on it. One green and one red you're on petrol. Flashing red - it's switching to LPG . Two green - you're on LPG. There are four smaller green LED's that tell you how much gas you have in the tank. In the centre there's white button that you can manually switch to Petrol if you want and back. But it's not necessary to have any input at all- it's all automatic. Switch over is set to engine temperature and Rev's I believe.

Cost. My wife's Xtrail was costing me 19p a mile in petrol and only 10p a mile on gas. That was petrol at a little over a pound a litre. My own car costs me 7.5p a mile on LPG. I'm told it's green but my motivation was to escape stupid petrol prices. Oh and you get £15 off your VED when you tell the DVLA. You just send a copy of the LPGA cert that Alan gives you and a copy of the invoice and they send you a new tax disc, requiring you to send them the old one. My extra Insurance cost after I told them was Zero.

While today's LPG cost is 55.9p a litre you will only get about 90% of the petrol miles per gallon because the gas' calorific value is lower than petrol. Unless you've a sports car you won't notice any deterioration in performance.

Few downsides to this except that there are too few garages offering Autogas for sale. But you can download autogas locations from the net as Point of Interest files for your Tomtom or Garmin.