LPG for a disco 2 v8

[rocky]

Hi, anyone had or has a disco 2 v8 that has been converted to lpg. If so are these engines ok for converting and what sort of mpg are they likely to achieve. Regards, Rocky

[sotal]

I can't see the point with LPG these days - it just doesn't seem economical anymore.

A quick search on the forum brings back an average of around 12mpg for the V8's on a decent multipoint LPG system.

On petrol they seem to do 18-20mpg - so take the midpoint of 19mpg

LPG costs 55p per litre petrol costs 93p per litre

So for £10 you will get 4 gallons of LPG or 2.4 gallons of Petrol

So at 12 miles to the gallon you will go 48 miles for £10 of LPG

And at 19 miles to the gallon you will go 45.6 miles for £10 of petrol

So for every £10 of fuel you will get a maximum of 2.4 miles extra

So if you do 10,000 miles per year you will need 833 gallons of LPG at a cost of £2085

10,000 miles on petrol would need 526 gallons at a cost of £2225

So taking that all into account the maximum saving an average user (10k/year) will be £140 over a year. For that £140 you will have to make nearly double the number of trips to the petrol station. You've also got extra costs to service the LPG kit (optional - but recommended). You've also got to run on petrol some of the time, you've got the hassle of some insurance companies not liking it or charging more. Also a lot of people report reduced performance on LPG.

If you need to do the conversion yourself a decent Multipoint LPG kit will set you back about £2500 and will take you 180,000 miles to recover the costs - not that I think it would last that long!

If the vehicle has already been converted then it would marginally be worth running on LPG (if you don't mind filling up twice as often etc) but if it hasn't been converted then it Definatley isn't worth fitting a kit, I'm really surprised that LPG kits are still sold - the numbers just don't add up!

If you really are worried about mpg and you want a Disco then the diesels are the only way to go. Even at the higher purchase price of diesel they will still return approx 60 miles to £10 worth of fuel at 28mpg.

Hope that helps

[nicks90]

i am sooooo gonna send the link to this thread to my brother who is determined to buy a v8 disco and convert it to lpg - saying it'll work out cheaper than a td5.......

[Bowie69]

Sotal, your figures really don't match my experience of LPG.... nor my father's or my brother's...

On petrol I used to get around 14mpg (average), and with bits bolted to it, I would get 13ish, on LPG I get between high 10's and 12 depending on motorway use or not etc.*

The difference in MPG between LPG and petrol is just not THAT great that it makes it uneconomical, with the current fuel prices I reckon on about a 30% saving on fuel.

Must also remember that LPG took longer to go up to silly prices than petrol, so it's likely to take a little longer to go back down (more inertia in the base cost) -I expect it to be back well under 50ppl by Christmas at which point it will be roughly half the price of petrol again.

Rocky, a good LPG system will net you minimal power loss, similar MPG and a lovely burble from the exhaust -get a pre-converted good quality multipoint and you probably won't pay over the book price for a petrol only version, and certainyl a lot less than the equivalent diesel.

HTH!

*This is a Rangie classic 3.9, yours will inherently be more economical I believe!

[sotal]

I was hoping somebody would come with an alternative view. I don't own a v8 so it is hard for me to know what figures they do so searching on the web is all I can do to get the figures.

As you say you've got a range rover whereas I was looking at Disco V8's. Can anyone confirm what sort of mpg they get with a bog standard v8 Discovery - I can find 3 or 4 posts stating that they get in the region of 18-20mpg.

It might be down to the fact that people post their best figures for petrol and worst figures for LPG?

I agree that prices might change but I'm just looking at the figures now.

Taking your figures of 14mpg on petrol (which I can't find anyone else saying they're that bad - on disco's anyway) and 10mpg for LPG

You will make a maximum saving of about £500 for every 10,000 miles you do, and you will have to go to the petrol station atleast 50% more.

Even at your figures it's still not worth paying for a conversion, a pre-converted might be worth it if it doesn't cost any extra.

What we need is more peoples accurately measured figures to work out if it really is worth it.

The following post suggests that the standard v8 disco gets 17+mpg:

http://forums.lr4x4.com/index.php?showtopi...mp;#entry320708

[mickeyw]

I have 2 vehicles, both 3.9s and both single point closed loop LPG but different makes and models of vaporiser and control device.

The RRC tends to manage about 12mpg on short trips to work, but also has been known to do 17 on a motorway run. Not sure about petrol mpg, never really used it on petrol. This has very road biased tyres fitted.

The Ninety, does around 12-13mpg on general running around and 18 on a motorway run. This is shod with M/Ts and carries a ton of carp inside. However motorway drives in this tend to be at legal speeds compared to the RRC.

It's been a long time since I used petrol in the Ninety, might be time to do a tankfull for the purpose of comparision, but I used to get around 16mpg running around from its original 3.5 carb engine.

I have been using LPG since 2001 on the Ninety, so my system is well and truly paid for now. Originally I had reckoned on 2 years mileage (about 15k for me) before I would get pay back. That was based on fuel prices at the time, about 32p/lit for gas I recall and petrol in the 60p ish region. There's a bit more than 30p difference between these two fuels now, so that should make pay back faster today

[teabag]

If your only getting 14mpg 'average' from a 3.9 engine there's something wrong somewhere.

I get 18mpg 'average' and therefore that means i'm getting sometimes 20 mpg on a run which I could better if I went a bit slower.

LPG is not for me.

[Quagmire]

I am getting around 20mpg (petrol) in my 90 with a newly rebuilt 3.5 running SU's. 99% of my mileage is Motorway cruising.

My old 2.25 used to return about 22mpg, driving at 60. I reckon the v8 can be more frugal if i use less loud pedal- but with the conversion only being completed 3 weeks ago i am still getting used to the novelty and the sound

On the 4cyl i used to get around 17-18mpg on gas. This saved me lots of cash, as i drive 70 miles a day commuting to and from work...

I guesss LPG is for some and not for others! If i can attain a similar consumption difference with the gas as i have so far managed with the petrol i will be very happy. I have three filling stations near me so I may as well use it. It also keeps the oil cleaner- important for the life of a v8...

I record all my mileage and fill ups in a little book i keep in the car, so my figures for the 2.25 are an average over months of driving and thousands of miles. I just hope that the average i have attained so far with the 3.5 is set to continue...

[Bowie69]

If your only getting 14mpg 'average' from a 3.9 engine there's something wrong somewhere.

I do drive fast, on country lanes, and rarely visit motorways, so 14 for me was average on petrol, on an unmodified J-plate RRC. Speaking to others on petrol V8 Classics, 14 is about right actually....

The 10-12 mpg on gas is now on mud tyres, 2" lift, winch, HD bumpers front and rear, tree sliders and various other extra heavy bits attached, which is bound to have an effect....

If you can get 18-20 out of a disco II on petrol, bank on getting 16-18 on LPG and with a bit of maths on 10,000 miles a year you save yourself nearly £800, based on 95ppl for petrol, and 55ppl for LPG*.

A better comparison can be pence per mile, with the Disco MPG figures and the same costs as above it works out at 14.71ppm for LPG, and 23.68ppm for petrol. To compare to diesel (108ppl)*, at 30mpg (optimistic?) you get 16.31ppm, so LPG is cheaper to run even than that..... even with the inflated LPG prices at the moment, with the bonus of a lovely soundtrack.

I agree, on an older vehicle like a Disco II the cost of the conversion pretty much rules it out, however buying a pre-converted one is the way to go, as said above they don't go for any more than the petrol derivatives.

*Prices taken from average prices around my postcode, provided by petrolprices.com

[disco_al]

interesting points on the costs involved.

i worked it out a couple of weeks ago for my 3.5, over the 6000 miles or so i have done in it, i reckon i have used about 2800 litres of gas, approx 616 gallons, and at an average of 52p/litre, thats £1456. Now if i had bought that much petrol, at say 105p/litre, that's £2940 - a saving of £1484. Even with the reduced efficency of LPG over petrol, i have still saved a huge amount.

to put it another way, it cost me £25 of LPG to get as far as Swindon the other week with a trailer on the back, it cost nearly £60 in petrol to get back.....

[sotal]

That was based on fuel prices at the time, about 32p/lit for gas I recall and petrol in the 60p ish region. There's a bit more than 30p difference between these two fuels now, so that should make pay back faster today

Work on percentages, when you started gas was 53% of the price of petrol now it's approx 60% of the price of petrol.

If you can get 18-20 out of a disco II on petrol, bank on getting 16-18 on LPG

They just don't get that in reality - you are talking more like 10-12 maybe 14mpg on a good run (from what I have read)

[Bowie69]

They just don't get that in reality - you are talking more like 10-12 maybe 14mpg on a good run (from what I have read)

I suggest that the system fitted is not set up correctly in that case, it really doesn't follow that just by changing to gas you lose 40% effieciency, it simply doesn't follow Maybe people just driving uber-conservative on petrol due to the cost of the liquid gold they are burning, and hoof it everywhere when on the cheap LPG

Any Disco II owners out there with a sequential LPG system that can give more info?

Oh, just opened my post, Countrywide Autogas that I get all my gas from has just reduced it's prices by 6ppl, now paying 48ppl, which is exactly half the petrol price around here

[trendkill]

I can't see the point with LPG these days - it just doesn't seem economical anymore.

A quick search on the forum brings back an average of around 12mpg for the V8's on a decent multipoint LPG system.

On petrol they seem to do 18-20mpg - so take the midpoint of 19mpg

LPG costs 55p per litre petrol costs 93p per litre

So for £10 you will get 4 gallons of LPG or 2.4 gallons of Petrol

So at 12 miles to the gallon you will go 48 miles for £10 of LPG

And at 19 miles to the gallon you will go 45.6 miles for £10 of petrol

So for every £10 of fuel you will get a maximum of 2.4 miles extra

So if you do 10,000 miles per year you will need 833 gallons of LPG at a cost of £2085

10,000 miles on petrol would need 526 gallons at a cost of £2225

So taking that all into account the maximum saving an average user (10k/year) will be £140 over a year. For that £140 you will have to make nearly double the number of trips to the petrol station. You've also got extra costs to service the LPG kit (optional - but recommended). You've also got to run on petrol some of the time, you've got the hassle of some insurance companies not liking it or charging more. Also a lot of people report reduced performance on LPG.

If you need to do the conversion yourself a decent Multipoint LPG kit will set you back about £2500 and will take you 180,000 miles to recover the costs - not that I think it would last that long!

If the vehicle has already been converted then it would marginally be worth running on LPG (if you don't mind filling up twice as often etc) but if it hasn't been converted then it Definatley isn't worth fitting a kit, I'm really surprised that LPG kits are still sold - the numbers just don't add up!

If you really are worried about mpg and you want a Disco then the diesels are the only way to go. Even at the higher purchase price of diesel they will still return approx 60 miles to £10 worth of fuel at 28mpg.

Hope that helps

erm. . .

dont be daft! My v8 costs me £32 to drive 100 miles to stoke on trent from west yorks

its just over £60 in petrol!!!

LPG IS A REAL MONEY SAVER! - My mate has a 300tdi and we worked out its cheaper for me to run my v8 than his diesel.

Theres a place in Stoke on trent that does gas for 44p a litre - so it's even cheaper getting back home from there.

Any my foot is PLANTED on the noise pedal all the way!

Cheers

[sotal]

That's a good price on the LPG.

I am genuinely interested as I was tempted by a V8 for my series. I am planning an engine change in the next year or so, and it's going to be a v8 or a tdi. From figures I have read and researched the TDI comes out by far the cheapest especially in a 200tdi form with the reduced weight of the series.

As you say we need more info from disco v8 owners!

I read on one of the official LPG sites (can't find it now) That efficiency could be up to 85% of equivalent petrol models, but this was only on new engines. In general cars could get up to 80% but older engine designs tended to be less efficient dropping as low as 70% (and they're trying to sell you the kits). So at that optimistic rate of 70% (considering it's a very old engine design) you would get 12.6mpg

[rocky]

Thanks for the replies, as my 300tdi needs some surgery for the m.o.t., i was looking at the disco 2's 'cause the bodies are somewhat better built. I have ruled out the td5's after hearing horror stories of the engine management system, so the only other alternative would be the v8, but reading your replies i think i will have to do a bit more research or maybe get a jap import 300tdi. thanks again guys. rocky

[sotal]

I wouldn't rule out the td5 I'd just budget to buy a nanocom so you can read out faults and clear lights yourself - they are only £200+vat so quickly pay for themselves.

I had a 300tdi, my father in law has a td5 I know which had more problems(300tdi) and I know which I'd have any day (td5). The td5 is higher mileage as well.

Looking at all the normal rot places on the td5 it is still in perfect shape, not a spot of rust to be seen. The only niggly problems he has had has been the rear door not wanting to open sometimes from the outside and the windscreen wipers forgetting where the park position was.

It's quite possible I had a bit of a lemon, but I'd still go for the td5 if I ever get another one

[nicks90]

If you can get 18-20 out of a disco II on petrol,

if you drive like a saint with an allergy to touching the accelerator pedal - then maybe

Father in law has jsut bought a D11 v8 with 50k on the clock from a chap down south. A local LR specialist picked it up off the seller and fully serviced it, valetted etc said it was absolutely mint - perfect condition. Anyway, he went down to london and drove it all the way back to yorkshire at a steady 75-80mph....................

12mpg!!!!!!

Even if it was lpg instead of petrol, that would still work out price wise as 24mpg. I can get 30mpg out of our chipped td5 D11 at 75-80 and almost 33mpg if doing 65-70mph. And after having driven his v8, yes its a bit quicker than our td5 - but you have got to rev the nuts off it to really notice the difference in speed. In gear acceleration lower down in the rev range (in other words real world day to day driving) our td5 is much quicker.

Not a V8 hater....much..... but i jsut cannot see how people can justify buying a v8 disco 2 and then converting to lpg. You can get pretty much the same sort of real world speeds/power from a moderately tweeked td5 and easily twice the fuel economy.

[q-rover]

Well a DiscoII will be either a GEMS or THOR engine so comparing it to old 3.9

Range Rovers is like comparing a new BMW compared to a 12 year old Audi.

I have a RR P38 4.6 GEMS engine. It is fitted with 265.75x16 General Grabber tyres

and only the speedo has been recalibrated.

On day to day driving i get between 1.6- 1.8L/10Km, however when going for a long drive

on motorway or main road I get between 1.2-1.3L/ 10Km.

These figures are taken from the trip computer and I have never calculated the accuracy of this.

I rarely drive more than 12.000Km a year, so for me an LPG conversion isn't worth it.

[kingo30]

I have a Disco 2 with a multipoint system fitted I get approx 180 - 190 miles on the motorway for roughly £30 of gas thats when it beeps at me and I switch to petrol, I get almost to my dads on merseyside from essex for £30 I think that is excellent for a v8 disco, someone who has not converted will be adding probably another £20 or more on top to cover the same distance