4.7 V8 LPG conversion, a proposition ? - boston

I have a 4.7 v8 Jeep Grand Cherokee that as you can imagine is quite thirsty!

I am currently looking into getting a LPG conversion done on it but have a few queries.

(1) I currently only do about 15-20 miles a day during the week and say 60 at the weekend usually. As i understand it the engine needs to get warm before the LPG can be turned on so basically this would not probably make it not worthwhile??

(2) Is there a loss in peformance?

(3) Are there differing types of conversions?

(4) Any other ways of getting better mpg? i.e fuel aditives etc?

Any help/experiences would be greatly appreciated.


Edited by Pugugly on 06/04/2008 at 00:59

Jeep Grand Cherokee Lpg conversion - Alby Back
So at a guess you are currently spending circa £2k a year on fuel? Assuming you had the conversion done at a cost of 2k but as a result halved your fuel bill it would take you two years to break even. So if you kept your car for another three years you would still only have saved 1k in three years. Not worth it in my view unless there is strong evidence that the conversion will signifcantly add to re-sale value or you plan to keep the car for a much longer time. In the latter case would it not be more worth exploring the cost of having a diesel engine fitted?
Jeep Grand Cherokee Lpg conversion - Screwloose

At £60 a week; it's never going to pay for itself - even if you could be sure the LPG tax break was staying. Only makes sense if you have your own tank.

You can have pure LPG conversions - this may be helpful for things like parking charges. Otherwise it'll start on petrol and switch over quite quickly.

You'll lose c.15% in power and economy.

Many different types; mostly rubbish fitted by fast-talking shysters.

Any other ways of getting better MPG - if only.
Jeep Grand Cherokee Lpg conversion - nick
On that engine you won't notice any loss of power. They normally switch to lpg very quickly. I had it done on a Cherokee 4 litre a few years ago, switching to lpg was within a mile. I was very pleased with mine but maybe I had a decent place to fit it. It cost about £2000 but added about £1000 to the value of the car (confirmed by a valuer when SWMBO wrote it off!).
If you are going to keep the car long term it would be worth it, unless tax regimes change significantly.
Jeep Grand Cherokee Lpg conversion - boston
Thanks for that.

Although on a daily basis i average that milege i would at weekend i do a variable amount and my plans are to keep it long term.

I guess my main concern is how long i have to drive from start until i can switch to from petrol to gas? I have read that the engine has to get properly warmed up in order to not do any damage to the car? Would a mile be enough to do that?
Jeep Grand Cherokee Lpg conversion - jc2
Also the tank will take up a significant amount of your luggage space or will be a toroidal which will take up the spare wheel space.Most conversions I have seen have been dangerous!!! Get it done by someone who will show you his previous work.If there are jubilee clips and Scotchloks,run away!!!!
Jeep Grand Cherokee Lpg conversion - thomp1983
slightly ot but jc2 why do you think jubilee clips shouldn't be used during installation of the kit? what other method of securing pipework would you suggest? of course i can understand why scotchlocks are a bad idea but unsure on jubilee clips?

Jeep Grand Cherokee Lpg conversion - jc2
Worm-drive clips don't apply pressure evenly on small diameter pipe-they go "D" shaped;there are a number of other pipe fastenings that don't have this problem.
Jeep Grand Cherokee Lpg conversion - nick
>>Also the tank will take up a significant amount of your luggage space or will be a toroidal which will take up the spare wheel space

Not necessarily. On the Cherokee I had converted, the original fuel tank was removed and a smaller one fitted and the gas tank in the remaining space. This gave about a third of the normal petrol capacity and a good range on gas.

Engines usually switch to gas very quickly. As I said before, often within a mile. No damage wil be caused. Check out the LPGA wbsite for approved fitters and go along and have a look at their work. If you have it done, tell your insurer who won't mind, as long as you have the installation certificate.
There's an awful lot of guff talked about the horrors of gas conversion, usually by people who have never had it done. If you find a reputable garage you should have no problems.
It might be worth finding out who Subaru use for their approved Forester conversions and try them.

Edited by nick on 06/04/2008 at 13:50

4.7 V8 LPG conversion, a proposition ? - sparky513
Its your lucky day.

I've just purchased and converted a 2002 Jeep Grand Cherokee 4.7 V8 Overland to LPG.

It cost me £1850 to convert down in fulham, I collected it on Saturday and promptly popped off to the garage to fill the tank up, I managed to get 48 Litres @ £28.00 and it lasted me 230 miles.

I drove around in London on saturday and then drove back to basingstoke. On Sunday we went to see some friends in Gosport and then back and then my final journey from basingstoke to newbury and then back.

Based on my Audi 2.4SE the JGC is a winning and that's before i take into account the congestion charge saving... woo hoo!!! i know that it's only for eighteen months but by then my business will be in a difference place and the addtional charge might not matter so much.

But before we all get carried away there is always a down side to everything...
On Sunday afternoon i noticed that the A/c was cold but wasn't coming out by force.

As it stands i have no idea what is causing it but it starts working for a few minutes every now and then
4.7 V8 LPG conversion, a proposition ? - neiluk
Hi Guys
We bought a JGC limited 4.7 v8 alreagy fitted with a LPG system on a 51 plate.

We have no idea when and where it was converted but thought it best to have it serviced, took it to a local LPG installer, he popped the bonnet and laughed (not very encouraging). He identified it as a "Romano" system which he said is a good system but it had been poorly fitted, he also said he did'nt do Romano's.

So Google search found us another local installer who did,

Took it down for him to look at, again looking under bonnet caused a laugh, but said he will service it for £150 whch I expected. He then pointed to 2 inline gas filters and said they will also want replacing at £50 each and then to a gas pipe that had "water" written on it that also needs replacing for about £15 so a £150 service has now gone up to nearly £300 ....... ouch.

And now to add insult to injury .......... she has started to intermitantly stall when ether stopped in drive or crawling in heavy traffic on either gas or petrol.................. arrrgh

Was this a good buy ................ any good reliable lpg service centres up in the Lancs Yorks area
4.7 V8 LPG conversion, a proposition ? - Lud
Daughter's bf, quite a serious car enthusiast who already has a Skyline GTR, was considering getting one of these as a runabout and I put out a query about it here. Consensus was about 60% against. I advised fairly strongly against on the ground that it would be expensive to run anyway, the reliability might well be iffy and most of all I thought my daughter, if she ever got to drive the thing, would be a danger to herself and others. Of course the boy friend would have been perfectly OK from that point of view.

They got a nice clean little Renault thing instead.
4.7 V8 LPG conversion, a proposition ? - lukasm
1. Well it will be long enough road to warm up the engine.
2. Yes there is a loss of performance.
3. Yes, it depends on what kind of engine you've got. It may be direct injection, or multijoint conversions.
4. Ride a bicycle. :)
4.7 V8 LPG conversion, a proposition ? - macavity
If concerned about the standard of the conversion then fit it youself:
www.tinleytech.co.uk/lpgprices.html then you will know how well it was fitted. Plus you will learn enough about the system to be able to service / repair it yourself when needed. Also it would be cheaper.

"Is there a lossin performance?"
what sort of performance do you need? how often do you take the 4.7 to the limit?

Plenty of systems/ conversions to chose from:
Nicholson Mclaren, zavoli etc

Diesel is easier.
Then DIY biodiesel www.guardian.co.uk/environment/2008/may/10/biofuel...y
Also look on youtube for biodiesel.

One of the problems with LPG is being able to find places that sell LPG You can find yourself planning you journeys around LPG stations, which might be easy where you live but on longer journeys it gets awkward.

4.7 V8 LPG conversion, a proposition ? - Focus {P}
If concerned about the standard of the conversion then fit it youself:

Given that the question was asked in April 2008, hopefully either the OP or someone else already has :-)

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