Beginners guide to LPG conversions

[Gordon@1962]

A little birdie told me some members may be interested in converting to LPG so as I’ve just had mine done I thought I’d pass on my experiences on the subject.
This article is not to debate the pros and cons of converting to LPG but to help those who are thinking of going ahead with the process.

My main consideration was where to fit the gas tank?
Most cars with adequate boot space are fitted with a cylinder tank but look what happens if you try this in an XJ-S

http://www.razey.karoo.net/images/LPG.jpg

For the XJ-S the best option would be a toroidal tank or the donut type.
If you want to keep your spare wheel go for the horizontal type, these are laid flat in the boot but if you want to save on boot space then go for a vertical toroidal tank.
I was a bit concerned at first not having a spare wheel but then did you know a lot of convertibles they make today don’t carry one either? They just carry a can of foam in the boot.
So that’s what I decided to do.
I opted to dump the spare and put the LPG tank in its place, but I’ve gone one better than carrying a can of foam and had my tyres filed with some stuff that will seal it before it goes down.

As you can see if fits very well indeed.

http://www.razey.karoo.net/images/lpg-tank.jpg

I’ve now fitted my old spare wheel cover over the top of the tank and it finishes it off even better.

I had no preference for what went on under the bonnet so I just let the guys do the business.
This is the finished job.

http://www.razey.karoo.net/images/lpg-EngineBay.jpg

The bottom right hand corner is the electronic box with the pump and other gizmo's underneath. And along the top of the cylinder head are the 6 gas injectors.

The fuel gauge can be fitted any where you want in the cabin.
Mine went here.

http://www.razey.karoo.net/images/lpg_FuelGauge.jpg

When in auto mode it will start on petrol and then after about 500 yds it will switch to LPG.
The button marked PJ is the switch to change from auto to manual in case you want to run permanently on Petrol at any time.


So there you have the installation.
And how does it run?

Great.
Everyone goes on about a loss in power but to tell you the truth I haven’t noticed any.
I’m not a Sunday driver and I love nothing more than ‘putting the pedal to the metal’ but I suppose the only way we’d ever know that answer would be at Santa Pod on a quarter mile run.

Economy……………….
I just refilled my gas tank for the first time and I put £21 in the tank, which took me 140 miles. But the next refill will be even cheaper as I've just found a filling station that does it for 5p a litre cheaper (39.9p) than the one I've just used.

Like I said at the beginning this isn't a debate on outlay over a return basis but to hopefully give a better insight into anyone else thinking of doing the same.

Gordon

[kelsham]

Hi most interesting but you left out the cost? also who fitted the conversion and do they do V12 cars regards Kels

[Gordon@1962]

Hi Kels,

I left out the cost deliberately as I had put a similar post in another forum and it started a long drawn out debate on 'how long would it take to get your money back'
I didn't want this post to get into that discussion again!!

However if helps here goes..................

The original quote was £1400 plus VAT but as is the usual there are always extras!
Because I wanted a vertical toroidal tank instead of the usual horizontal tank it was an extra £70.
Then the XJ-S needed a different set up under the hood which was an extra £120.
I then wanted to have my tyres filled with the stuff which seals them if you get a puncture, which was £68 and then the biggest cost was the dreaded VAT! (£291.90)
The good news is he knocked me a little of for the labour as he knew me through another friend.

A Grand total of £1959.50.

I had originally priced up another company outside of town but they were slightly more expensive, but what swung it for me was the FREE loan of a car while he did the job.

The company is called Autogas conversions based in Hull, East Yorkshire.
I'm not sure if they do V12's but I imagine he will as I've seen all sorts in his garage from Chelsea taxis to a 6L V8 Hummer.

[poprivet]

...another forum and it started a long drawn out debate ....

Best not mention what welder is a good buy then

Great post Gordon, I enjoyed reading it. Keep us informed how it performs.
Pop

[kelsham]

Gordon thanks for the reply, I suspect that discussions about how long to repay outlay will become meaningless next time you fill up and receive the immediate cash saving, allowing you to use your car without worrying about paying for the next high cost fill up. What range are you expecting from the torroidial tank? I think it looks great. and addresses my main complaint about installing L.P.G. Keep us informed of satisfaction levels regards Kels

[GlennH]

Hi Gordon,
Excellent post. Really good to see the details of a conversion. I think the tank you went for is perfect for the XJS.
One thing puzzles me on the economy figures you posted. Only 140 miles on £21 of gas is dreadful, it is less than 14mpg. Tryping error?

Cheers and regards,
Glenn.

[Gordon@1962]

Well to be honest I think it must be my style of driving.
I'm either stuck in traffic or doing 80mph down the motorway, so usage would always be a bit on the heavy side.

I used to get around 17mpg, but they say you can expect 2 - 3 miles to the gallon less with LPG.

I can get better on a run, say 24mpg but its been ages since I've gone for a long leisurely drive.
That was my first refill, so I'm wondering if I've made an error with my figures.
However what I want to do is keep a record over the next few months and see if I can work out a true average

I always did wonder why my car was heavy on the juice, but what I'm really happy with; is regardless of what my car does in mpg compared with other XJ-S's I now know my fuel bills are now a lot less than they were before

[ptjs1]

Gordon,

Tks for the post - really interesting. Autogas in Hull have been going for some years now. I suspect your system is set the same as most which is to cut over when the revs rise above 1200 rpm but then drop back below that figure. Therefore, I always blip the throttle at rest until the lpg cuts in, otherwise you can theoretically drive down the road and unless your revs drop to 1200 the car can stay on petrol for some time!

It will be possible to force the system to start on lpg but I think it's quite helpful to keep a dribble of petrol going down the injectors each day to stop them gumming up. The only time I had it starting on lpg was when I had once run the petrol tank dry, but nowadays I always make sure that I've got a gallon or two of petrol in the tank.

I wouldn't worry about the consumption on just one tank. You really need to keep a check on each tankful, if you're interested in the figures. I get relatively worse consumption in my Range Rover on lpg on "around-town" mileage than I do on long steady runs. You will also get minor differences on how much you can get in the tank depending on the weather and the pressure that the individual filling station has on their tank that day. A tank will only fill to about 80% of capacity because of expansion but I can definitely get a bit more in when the weather is really cold.

Anyway, good luck and keep letting us know how you're getting on.

Paul

[Gordon@1962]

Just a quick update.............

In the month of May I did 604 miles at a cost of £104.31 for LPG, compared with 526 miles in the month of February at a cost of £160 of petrol.

A quick calculation works out at 30p a mile for petrol and 17p a mile for LPG.

[ArtyH]

Hi folks, just a quick comparison, I got my S type 3L converted about 3 years ago for a cost of £2000, it is an AEG system. I was told to run the car for 10/15 miles every month on petrol. I do roughly 10 miles to work each day so its 20 miles return and whatever casual mileage is done. This usually returns 300 miles on a full tank, however I still have to put about £10 petrol in every other tankful. My system works on temperature to switch over to gas. I never know when it changes over as it is so smooth. It should also be known that the gas side of things needs a service every year and this for me costs around the £40 mark.
There are two types of delivery system that I know of, first is the single point injection type and secondly the multi point system. It obviously depends on the engine type what system is used, so the more injectors the higher the price. I was quoted £1500 for a single injector system for my XJS celebration and approx £2000 for a multi setup, this was from Granger Farm Systems who are based in Morpeth Northumberland, as a big incentive they offer a reduction of 2p per litre for their own conversion customers. I am not affiliated in any way to the company, in fact I have to pay full price ( 43p/L ) as I did not get my conversion at their garage, a mistake over what system to be fitted between myself and a staff member, nuff said.
Hope this helps anyone in the Northumberland area who is considering a conversion, ring Michael Grainger and speak to HIM personally so you do not make the same mistake as I did!

[Brakebuster]

Gordon,

first of all, good stuff on the conversion, and having the ' balls ' to do it , and post it on the forum,

however, i have tried to get my head around the figures , it seems that for a similar mileage you are paying £60 less for the gas, is this correct ?

but you had to outlay £2k for the work.... yes your weekly (?) fill-up cost is less, but you have to recoup the initial outlay before you can do any comparison, because you have to factor in the initial cost of the conversion , surly...?
this means you are not saving any money at all untill the £2k has been negated with the 'lower' running costs ( plus annual servicing of the lpg etc )

I'm not trying to provoke any type of argument here, just understand the justification

BB


2nd eddit,lol,
i currently put £60 a week into my XJ8 and get around 350 miles from her, but thats the price i'm willing to pay for driving such a car....my previous car was a new 2.2 turbo diesel VX , that took £50 to fill and i got about 420 miles from it , so the jag aint that bad in compasison

[poprivet]

Eurotunnel still ban any LPG fuelled vehicles for some unknown reason.

Many years ago I worked for a company developing vehicle use of CNG (Compressed Natural Gas). One of the brilliant aspects of this was a very quiet, slow-fill but very high pressure compressor so you could charge up the car from your home gas supply every night. As there was no practical way of taxing the gas used for road use the then government effectively blocked any development. The system was adopted for use by a few bus companies, but using a conventional quick fill system.
Pop

[Gordon@1962]

I'm not trying to provoke any type of argument here, just understand the justification

My idea was to find an immediate way to make a monthly saving to my fuel bills.
I knew from the outset that if I did the Maths it would leave me thinking I would need to run the car at least a year before I'd break even.
With a touch of sarcasm another choice could be to put £2,000 in a little post office account and every time I fill with petrol draw on that, but hey once it’s gone its gone!

But that wasn't my line of thought.
I had some redundancy money from my last job and felt the urge to spend some money on my 'Jag'
I know it might seem frivolous to some but there I was with a wheel barrow full of green stuff and thought to myself shall I have a holiday or spend it on the house or buy a new car or just save it for a rainy day?
But wait a moment what about my XJ-S.

I could have a respray or new carpets or some nice new alloys but wait a moment wouldn't it be good to do something totally different?
What about making my car cheaper to run each month, being good on the environment and getting one step ahead before the government introduces more taxes on the so called gas guzzlers (god I hate that term!)

No one ever knows how long they will keep a car and my plan was for at least another two years or more. (fancy a soft top next) So in theory I will make a saving and on another plus side I’d like to think if I ever sold my car at a later date it I would have more potential buyers due to its cheap running costs.

So basically that was my reasoning.
I don’t expect anyone to agree with my line of thought but I thought it might be useful for you to have a better understanding as to why some people often look at things on a different level apart from a monitory return.
After all how many Jaguar Enthusiasts would only spend money on their cars to get a financial return at a later date?
I would argue that those people aren’t really true enthusiasts but those seeking to make a quick buck out of the classic car fraternity but that’s another story!

PS:
I understand that my original article has been published in this months Jaguar Enthusiast magazine?
I haven’t seen it yet as mine hasn’t arrived yet but I hope it sets out to do what I started out to do. That is to inspire other XJ-S owners into contemplating a conversion.

[ptjs1]

Gordon,

Your article is published in all it's glory in this months mag and personally, I feel it reads very well! Well done and thanks for submitting it.

I hope it encourages others to submit articles. Many of our Forum contributors have a wealth of material about the trials and tribulations of their XJS's which would make great articles. So, come on guys & girls, get tapping away on the keyboards and your own pride and joy could be seen in print. ( I suspect that Gordon has also added to the value of his car as it is now "as featured in Jaguar Enthusiasts Club magazine"! Must be worth another £2k, at least!).

Paul

[jthorne]

I have a 6ltr which is converted to LPG, it seems basically like two 6cly systems put together. I believe it was put in by the Rotherham Jag Centre if that helps anyone......