LPG Conversion on 5.3 V12 XJ-SC

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    • #9918
      Roger Farmer
      Participant

      I have recently converted my 1986 XJ-SC for LPG and I have placed a couple of images in the photo gallery to illustrate what I am talking about. I have been using LPG on my other cars since 2008 and have encountered no problems with its use whilst saving over £12,000 (including costs of installation) on fuel costs over this period. I had the conversion done in August and it has worked very well indeed. I have a 80 Ltr tank installed in the place of the spare wheel and a relocation of the battery to the right side rear wing.

      There are a number of advantages with LPG, particularly in long term cost! My XJ-SC will do about 17 mpg on short runs and with LPG at 60p a litre at my local garage it halves the cost of my fuel. In addition the car tax is slightly cheaper and I believe it is not subject to congestion charge as it is taxed as a duel fuel vehicle. The other benefit is its effect on the 5.3 engine. LPG burns much more cleanly than petrol an this reduces wear on the engine. LPG cars can and often do rack up galactic mileages without any real detriment to the engine. Because it burns more cleanly, LPG ensures you very low emissions if you are worried about your MOT!

      On the down side, I am told that LPG will reduce the power output by as much as 10% however if this is the case I have never noticed. I use a Daimler V8 4 Ltr as my daily runabout and there seems to be no lack of power. There is a cost to V12 installation (£2300) but if you are going to keep the car for more than 15,000 miles then I would say it is definitely worth it. The presence of a certified LPG system may possibly enhance the value of your car but purists will probably not like it. It depends whether you actually want to drive your car or just keep it as some sort of investment. If you do convert, try to raise the value of your car as a set value with your insurer as my experience of insurers is that they consider LPG conversion as giving no additional value to the car.

      I would stress that V12 installation is more expensive because it uses 2 sets of 6 jets for the V12 engine. If you are converting a straight 6 it would be around £1500. The work on my car was done by Neal Muggleston in Lincolnshire, he is a JEC member and fully certified fitter specialising in Jaguars.

      Roger

    • #9922
      Alan Tew
      Participant

      Hi Roger,
      Do you travel without a spare wheel or does it just sit in front of the tank?
      Alan

    • #9924
      Roger Farmer
      Participant

      Hi Alan,

      I keep a 300 ml can of Wynns Tyre Fix in the boot insted of the spare tyre. I have had a puncture only once in the last 20 years and the can enabled me to drive safely to a tyre stockist. The tyre had to be replaced of course but I could live with that for the convenience.

      Cheers

      Roger

    • #9997
      Laurence Jones
      Keymaster

      Thanks Roger

      I’ve written this up as an article for all members to find and read in the future – Found Here

    • #10012
      Roger Farmer
      Participant

      Thanks Laurence, I hope it is of use to someone. Did you get the article on woodwork?

      Cheers

      Roger

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