Landrover V8 Petrol v LPG

Hi all, my parent have a 95 Crossroads (Landrover) with under 70k on it. It is absolutely mint condition.
My sister and BIL live up on a farm up the east coast and are looking at getting another wagon. They currently have a Nissan Torrano (sp) POS that it is, they must have replaced the whole suspension and drive train at least once not to mention tyres, brakes motor works etc.I know gravel roads are hard but this thing needs work damn near monthly.

Anyway, the folks dont want the V8 trunk anymore and sugested my sister and BIL convert it to LPG for $4500k and drip feed M&D $4k as they can pay it.
BIL and sis reckon the LPG will only give them extra 3km per whatever and its not worth it.
Im trying to find some hard data to see how they get that figure.

Any ideas!

Well you can expect less KMs per litre of LPG - the Falcon (for instance) is 12.5l/100km in the dedicated LPG version and 9.9l/100km in petrol. And that's best case because the vehicle came from the factory that way.

I really doubt its going to be worth it

There will be a saving, but the mileage they need to cover to recoup most likely won't be worth it. Can't say i know about the v8 landys, but my old ex taxi falcon would get 7.5l/100km on 91 and about 11 on LPG cruising at 100kmh, from memory LPG was marginally cheaper, but the hassle of shorter range per tank, annual LPG wof and boot space taken up by the tank wasn't worth it. If you're worried about furl consumption with a v8 land rover you are driving the wrong vehicle.

Thx for the replies guys.yeah a V8 landys isnt the best for fuel consumption, but its got to be better than 30k+ for a recent 4x4.
M& D's landy in in great condition and I would put money on it lasting better than any wagon my sister could get for 30K

I,ve had a few lpg powered Range Rover v8,Discoverys(same motor as the crossroads) and wouldn,t go pastthem, they run cleaner,last longer. You cant beat them for Saftey,comfort,driveability on all types of roads,both rough and smooth.they tow anything anywhere. If the Crossroad has only done 70k them grab it ,convert to lpg and never look back.You will have a brilliantly safe reliable vehicle.just my opinion.cheers AJ

Can you give me any idea on km/p gas tank petrol v lpg and cost etc!

You'ld have to figure out where your nearest LPG filling station is, if ya live remotely, and I'm pretty sure those discovery's can only fit a very small tank, and then you will have no room left in the boot at all. As ya know the boot's ain't the biggest. for the 8-9k you say you'll spend I'm sure you could get an easier vehicle to live with for that price.

I've had LPG, but not in an discovery, I would hazard a guess you wouldn't get less than 16L per 100km. Going on what you say, rural - gravel roads. That's total speculation of course.

I looked at buying a LPG RRhe said had to fill it twicecompared to tank ofpetrol .Dropped the power a bit tooDeclined in the end as tankwasted too much space in the back & no room for my kon tiki & winch& gearso got 3.9 disco .

Hmmm, any Land Cruiser from 1999 or later will cost them 30+, it just seems a shame to waste this wagon.

Just run it on petrol. Sure it'll be thirsty but that's something you have to live with in that type of vehicle

I used to run a 2005 4.0 litre 4 x 4 courier on LPG. Never got better than 17l/100km.

Hi solster,

Here is a little bit of how and why which may help.

* Firstly LPG has less energy per litre in it than petrol. Thats why you always have an economy loss. Be wary of claims of very similar economy to petrol as the only way that can happen is if the petrol injection/carberattion system was running inefficiently for some reason.

* Types of LPG system.
Just like petrol injection systems have improved over the years so have LPG systems. The type of LPG system will greatly affect just how much loss of economy you get. Using figures from the likes of a late model Falcon will not give you a useful answer as the Falcon is able to be fitted with a modern multi-point LPG injection system as it has a modern multi-point petrol injection system as factory.
I don't know anything about the V8 in the Landrover, but will take a guess that its a single point injected Rover V8. With that sort of system you will be able to get a fairly efficient single point LPG system to fit easily. So comparing like for like I would say to be safe expect a 30% reduction in economy based on what that particular Landrover was getting. Some LPG systems claim you only lose 25% etc but these claims are usually a bit optomistic and its better to err on the side of caution for working costs etc.

Its worth noting too that some people will be using old fashioned LPG systems on their Landrovers so be wary of comparing figures with others, best to work your own math based on the 30% loss.

* How to work it all out!
O.K so all you need to do is work out the vehicles current economy in dollar terms based on the price of petrol in your area.
Then adjust the same l/100km figure to account for a 30% reduction in economy and multiply it by the cost of LPG in your area.
Then you can simply work out the difference and how many km's it will take to pay off the cost of installation. Don't forget to add the cost of an annual LPG and 10 year Tank cert to the LPG costs as well.

* Other stuff that may help.
LPG price will vary over time but not necessarily perfectly in step with Petrol. The reason LPG vaguely moves in relation to petrol is that manufacturers can switch to LPG for producing items like plastics when the price of oil get suitably high in relation to LPG.

Given our dollar is historically very high at the moment and we still have high petrol prices it is possible that LPG may become even more economical in future. I don't have a crystal ball though and there are many factors at play so its hard to predict, especially as we are living in unprecedented global financial times. and not unprecedentedly good I am afraid.

If you have someone who is mechanically minded in the family you may find you can import and fit you own modern LPG system for less than $1500 (possibly lots less). I have seen these kits available and know them to be of good quality. What I don't know is how you go with equivalent NZ standards and installation certification etc. It would be worth investigating though in my opinion.

Good luck with it all, its well worth doing the math on it in my opinion. Just remember to trust your own workings over any anecdotal figures for the reasons explained. If you get stuck on it yell out and I will look up the economy figures for the vehicle and walk you through it.

Just one more point. It's worth noting that you can usually fit a multi point LPG injection system to a single point factory petrol installation. Its generally a bit more involved though with regard to the ECU which can't "piggyback" on the factory one easily.
This is worth noting though as if you find your figures are not looking favorable for LPG it could be worth looking into further. Sometimes where you go from single point factory injection to multi point aftermarket with V8's you can improve your 30% loss considerably because you are balancing the loss of energy per litre with LPG with a gain in engine efficiency.
It would be worth finding out more about what sort of LPG system your Sister has been quoted and what percentage loss of economy the installer thinks they will get.

If you run it on 91 and put the extra $20 into the fuel that you would have spent on the LPG system install it will last you for years. On those roads in four years it won't be worth anything anyway. once the km get up depreciation will be huge. Best to get a bargan and try to sell it if you can. ( I know that is not the idea). Good luck.

you can not fit vapour injection on the disco 1 as they are grouped injection.Must be sequential injection.LPG through rockgas card is $1.10 per litre.And is not likely to increase in the near future.

If LPG is $1.10 per litre with the rockgas card and LPG vehicles typically use 20-25% more fuel (lets use 20%) then the average cost per litre equivalent is $1.32. Petrol is about $2.05 or so. - say $0.70 per litre more.

If conversion cost is $4500 as listed above, you need to buy about 6,500 litres of petrol. At 13L/100kms thats about 50,000kms of travel to recover your initial costs, ignoring the extra costs of the LPG wof, lost income of the $4500 and stuff like that.

Big question, is a Rover V8 good for another 50,000 kms! If they want the LR then buy it and run it on petrol.

Not just the engine you need to look at the whole vehicle.

The maintenance items mentioned on the Nissan (i.e. tyres, brakes and suspension components) aren't going to magically last forever on the Land Rover.

i want to buy a land rover, they should buy my old landcruiser then they dont have to worry about wrecking anything or spending too much on a vehicle then i can buy their landy.