yes you are right Richard if you are the lucky person to purchase a car on gas thats not 10 years old you get the savings straight away , unfortunately the original purchaser gets nothing as there is no resale value of the unit . with the standards in Europe you have reason to do it as well
PS my daughter purchased a patrol on gas and then found out when she brought it into tassie it had to be inspected , this was a 1000 dollar job plus a new tank or 250 dollars to remove . it was removed , the tank which was still halve full sat in the yard for 2 or 3 months and then started to leak , it took 2 days to empty , the tank was just over the 10 year mark . i have 2 other gas tanks with gas in them that are considerably older so i would like to empty them , is their a safe way to do that or just put power to soliniod and open valve and leave it in the paddock to vent

Although tanks are dated for a 10 year life, they are never checked here so many are much older. Underslung tanks can rot away in less time than that while a wheel well tank can last far longer. I've got one that is 15 years old that I took out of one car and it still looks like new. My car was converted in 2008 so I assume my tank is now 3 years out of date. The MoT test includes a brief look at the LPG system, the fuel system (irrespective of what type of fuel) is checked for leaks and security so on a converted car, both the petrol pipes and LPG pipework will be checked. If you've got a gas leak the tester will notice it anyway while he is under the car unless he's got no sense of smell.

If you have a high pressure pump capable of pumping liquid gas, you could use that but then you need somewhere to pump it to. Put it somewhere away from sources of ignition and with no holes in the ground or drains (as the vapour is heavier than air and will pool in them), a couple of long bits of wire onto the valve and connect a battery at a safe distance.

yes this tank was an external tank , leaked around the seal on the actual tank where the level indicator is mounted , easy to see it was iced up . the long piece off wire was the option i was going with for the other tanks .

Marshall8hp wrote:

Hence my comment. StrangeRover is getting 14mpg on the road, I’m getting 21mpg, I.e. 50% better economy.

I’m not saying running costs are less on petrol, we all know they are not. But I’m not sure they are as great a saving as some feel they are. What would you consider a reasonable time to depreciate the LPG installation cost, as that should be taken into account. Say £500 year over 4 years for a good multipoint system?

We are pretty used to fitting and running LPG here. You have to appreciate that Australia probably has the highest density of LPG cars in the world, against the number in the total fleet. It has been a common fuel here for 50 years and every service station carries LPG, or at least it is rare to find one that doesn’t. If you have LPG fitted to your vehicle in NSW, then your annual Pink Slip inspection (what you would call MOT) can only be done by a specialist LPG MOT station as the whole LPG system is gone through annually as part of the vehicle safety check.

50% better economy but the fuel costs in the UK are generally double for Petrol over LPG so it's well worth it over here. It sounds like your government didn't like losing the revenue!

The installation on The Duchess cost £1500. From my figures in my earlier post I'm saving 12.9 pence per mile (@64ppl for LPG which is the national average) so that paid back in 11,627 miles.
I normally fill up at ASDA which is currently 52.7ppl in York so it was actually a bit quicker for me.

247mi from the the last fill..

Getting better it seems very happy after replacing both O2 sensors, i've managed to balance a coin on the intake while running on Gas which is not too bad.

No difference in power either it seems feels quite sprightly on both fuels.

263mi from 75litres I ran her until it switched over to pez..

So that equated to roughly 16mpg..

which isn't too bad, the last fill up was £42

Have an interesting question ... have a tank like Richard (80lt, max fill 67/69lt), and my average runs are in the range you guys described. My best long distance "quiet" running was around 370/380km (230/236mi) on hwy ~120km/h (75mph) with my old and crappy Falken ATs. On a faster pace, say 80/85mph it drops to around 300/320km (185/200mi).

This said, I've been toying with the idea to increase range, for a number of reasons not worth bothering you guys with right now.
As I got a 2yo bottle I'd rather not mess around with the spare tire well and start hacking metal away at this moment, but I am wondering what would be a good choice. I see the underside offers almost no space where to put anything, unlike older LRs.
What about to drop the fuel tank and find or make a smaller one (say max 20lt), reusing its fuel pump and level meter, and use the remaining space to fit whatever can be fit (tube type or toroidal). I've seen this mod in small 4wd like Suzukis and Ferozas and it seems to work, anyone has even ventured or seen that on a P38?

The Classic didn't have a suitable spare wheel well but plenty of space underneath although it wasn't particularly usable. Most ended up with a pair of 'torpedo' tanks between the sills and chassis rail or a vertical toroidal on one side of the boot (my 93 Classic LSE had that on the LH side and with the spare wheel on the RH side. With a carpet spare wheel cover over both it looked like I had 2 spare wheels). A number of companies made small petrol tanks, such as this one for the Discovery https://lpgautosupplies.co.uk/shop/lpg-kits/land-rover/36-ltr-pet-tank-drawing-disco-2-3459/ so an LPG tank can be fitted into the space freed up by that. The other alternative with a P38, is a cylinder tank in the boot behind the rear seats but you do lose boot space then. You can always make it removable so is only there when you need it.

I've wondered about putting a tank, with quick connect pipe connections, in a small trailer and towing that behind me when doing really long journeys. A range of over 1,000 miles should be sufficient at avoiding the countries where LPG is expensive so I only fill up in the cheaper places.

That is one of the reasons ... traveling cross-country some places are best to avoid if possible, LPG wise.
The tank you mentioned looks like what I am talking about, but I doubt no-one ever made something like this for the black sheep the P38 ... I guess I will drop the tank on my donor rangie and play around.
Will update when the time comes.

I cannot use the boot, otherwise a "fit and remove" cylinder tank would be simple choice. If I had thought of it earlier, when I had to replace mine I could have made some hack and fit a larger one, or two cylinder ones like the mod that was advertised time ago by RPi http://www.v8engines.com/faq-lpg-Gems-twin-tanks.htm
Next time ... for now will consider something in place of the petrol tank. Thanks!

The design of the Classic lent itself well to fitting a very unusual design of LPG tank underneath... a trapezoidal design tank. But that design was almost uniquely used on Classics, high cost and unusual to fit even on Classics. As has been said, most Classics had other tank options fitted, mostly cylinder tank in the luggage area or vertical toroidal tank in the spare wheel location.

On a P38 the biggest size tank that will fit flush in the spare wheel well is 720mm x 270mm. Such size tank will be rated at between 84 and 95 litres, the lower figures for 30 degree hollow centred designs, the higher figures for zero degree or 4 hole designs. It is possible to remove the bottom of the spare wheel well to fit a deeper tank (more than 270mm and 720mm wide tanks are made up to 350mm deep) but the P38 design has a rear antiroll bar close to the spare wheel well which cannot be fouled by the fitting of any deeper tank, hence most tanks in P38 spare wheel wells will be 720x270.

On P38's a second tank can be fitted in the luggage area. Such tank can be made removable using (e.g.) hanson fittings. I don't own a P38 but my Elgrand has a 720x270mm 95L 4 hole fitted to the external spare wheel position and a couple of hanson fittings that extend into the rear luggage area - currently I have an 80L cylinder tank hooked up to those hanson fittings and I refuelled with 175 litres of LPG today. When I no longer want the additional cylinder in the boot fitted I will very easily remove it just by disconnecting the 2 hanson fittings. My 720x270 95L 4 hole has working capacity of 95L because I modified it to fill to 100% instead of the usual 80%. My 90L rated cylinder fills to 80L.

When you have the ability to add a 2nd tank inside using quick release gas connectors you're not just limited to adding that single extra tank,. I could add any number of extra tanks and carry them inside, switching tanks as easily as switching between quick release connectors. The permanently fitted 720x270 external tank gives me 300+ mile range, the 80 net litre cylinder gives me around 300 miles on top, I could easily add a 3rd / 4th tank. Just with 2 tanks fitted I can tow my large caravan 500 miles without needing to refuel. I have thought about removing the petrol tank to permanently fit an LPG tank in it's place - which might (combined with just the 720x270) give range on LPg of 600 miles or 900 miles with 1 additional tank.. With that kind of range on LPG you don't need the facility to be able to run on petrol.

Thanks for chiming in, Simon! Very useful information. Obviously your figures are helped by having an efficient engine design, as oppose to our venerable (and antediluvian) RV8 :-)
My tank is indeed 720x270, back then when I had a shop with the colleague we would 'tweak' the tanks to allow a few % more refill - with the obvious safety factor diminished - but this replacement I had to do it through "official installer" and we would not bulge to pass the nominal 80%. Also, here we do not have such tanks (95L), max capacity for 720x270 is 84/89L. Pity.

Good idea on the quick fitting connectors, but when I do long travels the boot of the P38 gets easily crowded, so I cannot really think in advance if I will have space for another tank, plus the idea to start drilling again boot and carpets to have another hassle in the form of a heavy ass removable piece of kit is dreadful. I am in a "lazy" phase of life :-(
Hence I was thinking to use instead the near useless fuel tank ...

I don't know the dimensions of a P38 petrol tank so can't advise what LPG tank(s) you could replace the petrol tank with if you wanted to run monofuel LPG.

For the old Discovery's it was common practice to remove the original petrol tank, fit a smaller petrol tank and LPG tank in it's place.

My tank is labelled 92L in the spare wheel well.

Oddly it routinely takes well in excess of 80 litres at most pumps. I usually stop somewhere around 85L myself. I've had on a few occasions the pump cut out around 65-70L, but the vast majority of the time i have to stop manually.

That much gas gets me around 200-220miles, which seems fairly poor given some of the other folks results, circa 11mpg.

I don't know the dimensions of a P38 petrol tank so can't advise what LPG tank(s) you could replace the petrol tank with if you wanted to run monofuel LPG.

Today I needed some stuff and was in the right place, so I took off the petrol tank from my "spare donor" P38, along with its cradle, and will take some measurements and see what can be done.
Since the tank has a stepped shape, with two different heights, I can see right away the pump will not be able to be reused, as it is in the larger area. Not a big deal, this opens up to lots of variants.
Not sure how the sender will work though ...

Aragorn wrote:

My tank is labelled 92L in the spare wheel well.

Oddly it routinely takes well in excess of 80 litres at most pumps. I usually stop somewhere around 85L myself. I've had on a few occasions the pump cut out around 65-70L, but the vast majority of the time i have to stop manually.

That much gas gets me around 200-220miles, which seems fairly poor given some of the other folks results, circa 11mpg.

Your calculation is a bit pessimistic. You are getting approximately 3 miles per litre which is 13.35mpg.

85L of LPG is 18.7 gallons.

200miles / 18.7 gallons is 10.6 MPG
220miles / 18.7 gallons is 11.7 MPG

Slightly off subject, but does an LPG conversion now make a p38 ULEZ compliant?
Dumb question but I have got a dirty diesel.

There is no LPG exemption for ULEZ. Some reports that 4.0 Thor cars have sufficiently low NOx figures to be allowed in anyway.

Scottish ULEZ has a 30 year cutoff though, so my old barge will be allowed in next year regardless.

Aragorn wrote:

Some reports that 4.0 Thor cars have sufficiently low NOx figures to be allowed in anyway.

There are multiple errors in the TfL database. A 2000 or later 4.0 litre Thor is shown as being compliant, despite being Euro 2, while a 4.6 Thor, which has near identical emissions figures and is also Euro 2 isn't. I've recently been working on a 2005 Rover 75 with an oil burner under the bonnet (thankfully, it doesn't need any engine work) which is Euro 3, so not compliant but it is on a personal plate. Putting that plate in correctly identifies the car as a 2005 diesel but says it is complaint whereas an identical one with the 55 plate, isn't.

The only exemption for LPG is for taxis that have been converted, at horrendous cost, by a specific company. It isn't taken into account for private cars unlike France where it is considered as clean as a hybrid.

I took some measurements, margin of error +/- 1cm

https://1drv.ms/i/s!Aog9VsSxOLcFm2GNeeOo7cS1pbe1?e=UCvpn9

As you can see from the stepped shape, I believe a tank that can fit in a "box" of say max 560x500x400 mm to be on the safe side, would be sufficient. I will start looking as see what comes up.
As for the fuel, the stepped front part is a trapezoidal shape (it escapes me the name of the "3D" version of a trapeze) max 200x420x560mm, which gives a volume of 47 liters, I believe ample sufficient.
There is no way to fit the OEM pump and sender, as it is positioned in the "high" part of the fuel tank.
A suitable aftermarket replacement will do fine. Anybody knows what is the rating of the OE pump (operational pressure and flow)?
Another benefit of a different pump would be to have a normal fuel filter!
There is plenty space ahead of the fuel tank against the chassis rail, working around some sort of EVAP canister.
I was thinking a cradle like used in the old Mercedes is ideal, as it holds both filter and pump in a suspended harness.