3 litre diesel Vs V8 on LPG - discuss

M@r]{ · Post by **M@r]{** » Tue Oct 04, 2011 1:51 pm

I've been just looking at 3.0d for the fuel economy, but someone has just reminded me about LPG.

So based on the facelift models can people give me their opinion on what they believe would be the better option and why? My budget will be upto Â£12k, although really it should be around Â£11k. So for that money I expect the mileage to be getting on. So petrol v diesel on that front? It will be used primarily by my girlfriend to do the weekly 200 mile round trip to London and back. Then once a month it will be used to tow my track car around.

malc1950 · Post by **malc1950** » Tue Oct 04, 2011 2:31 pm

I have a 2004 e53 facelift diesel remaped that returns 28mpg average and up to 43mpg on a long run at 65 to 70mph,

Neil48is · Post by **Neil48is** » Tue Oct 04, 2011 2:42 pm

I have an LPG converted 4.8is and on a Â£50 fill up i am seeing between 240-250 miles with mainly short runs,i expect around 280 on a decent run. I estimate i'm doing around 30 mpg knocking around and approx 35 mpg on a steady 70 mph run. And you get all the fun and noise !!

gobiman · Post by **gobiman** » Tue Oct 04, 2011 4:23 pm

I would widen the discussion to diesel vs LPG V8 vs V8
I used to have a 3.0d bought from new in 2004 and traded it for an immaculate and much lower mileage 4.8iS from the same year.
My like-for-like mpg between the two is 20 vs 27 ( a mixture of central London and fast motorway ). The MPG difference is not as vast in my view as some claim.
The like-for-like cost second hand of a diesel is much higher - I reckoned 4-5k when I bought my 4.8 and the V8s are often better specced. Also there are plenty of well-looked after private vehicles around. You need to do your own maths but the higher depreciation of the V8s made them in my view a much better purchase if your annual mileage is modest. Also petrol is a few pence cheaper. Against that insurance is higher.
200 miles a week, assuming say 45 weeks a year is only 9000 miles.
Also there's no turbo to blow and a glorious well engineered and unstressed powerplant. And of course the V8 burble.
LPG is only worth it if you do the miles.
I had actually wanted a facelift 4.4 (320 bhp) but was seduced by a 4.8iS.
My view would be not to dismiss the V8 until you've done the maths and worked out your mileage.
Good luck - both petrol and diesel are cracking cars

tombs · Post by **tombs** » Wed Oct 05, 2011 10:17 pm

I agree with the above, to take a V8 and convert properly is going to cost around the Â£2.5K - Â£3k mark. But to make that pay you need to be doing the mileage and probably keep the car for a while. I bought my 4.4 with a BRC lpg conversion done so every fill up is a saving, its worth it if you can find a car already converted imo.

JimmySpeed · Post by **JimmySpeed** » Thu Oct 06, 2011 9:04 am

I would take the LPG everytime ( although I would - I think it was my post that got you thinking about LPG)
The 3.0d is not that economical in the X5 as it is in 'cars' due to the sheer size of the X. Thus it works hard and drinks more. The V8s are unstressed in the X and you avoid the turbo and injector issues.

Buying one already converted is the best bet, as it's like it's free that way. The actual conversion is quite straight forward on these particular engines so LPG system problems are rare as long as it's been done by anyone other than a cowboy installer.

CondorX5 · Post by **CondorX5** » Thu Oct 06, 2011 10:47 pm

I would choose the V8 every time, all the time, but I would never convert to LPG - when I realised that my new job would mean clocking up the miles, I accepted the diesel company car and keep my beloved 4.8is in all its glory in its manufactured state, as intended, to run on petrol. I know LPG systems have improved over the years, but I really do not want to lose my spare wheel for a can of goo and have hell's own battle trying to access the battery / BT module / anything under the "tin hat" ie under the donut tank. Plus it will mean many complications on my warranty and "modifications" to list on insurance. I was very put off LPG by Range Rover owners whose 4.6 V8s readily popped their clogs some years ago as a result of the higher running temps of LPG......my P38 RR never had any major engine problems, clocked up 150 000 miles on her and sold her running sweet as a nut when I bought my first X5 - I for one, am really pleased I never had her LPG converted and will not easily convert an X5. I'd rather keep a second diesel car than mess up the beauty that is my 4.8.........

Raj · Post by **Raj** » Thu Oct 06, 2011 10:51 pm

I agree with Condor. I have contemplated doing an lpg conversion but when you factor in the cost, etc and the possible issue with warranty or general maintenance I can't justify it (well not anyway). As said, if i need to I'd rather buy a Â£1K runaround to do the miles in and not worry about.

4.8isDriver · Post by **4.8isDriver** » Thu Oct 06, 2011 11:17 pm

[quote=""Raj""]I agree with Condor.[/quote]
+1 i love my V8 nothing beats the noise and pulling power! and since the remap by Jason economy has actually improved!
a while ago i planned to stop at a partucular fuel station, as i got there it was closed for revamp and i had 1mile remaining according to the trip, abit of slipstreaming/hyper-mileing on the m4 and i was 8miles further at the next fuel stop and according to the on-board computer managed to achieve 32.4MPG!

JimmySpeed · Post by **JimmySpeed** » Thu Oct 06, 2011 11:29 pm

Maintenance for me means 1 LPG service a year at Â£60.

LPG may run at a higher temp but the engine runs cleaner on it maybe due to its lower calorific value, my oil after 5k is as clean as the day it went in, my jaw literally dropped when I saw it. I have no qualms being converted but then again I have no warranty to worry about. As far as the drive is concerned, changing tyre brands makes a bigger difference than running on LPG - I sometimes flick it over to petrol and back to LPG a few times on a run, and there is no noticeable difference. Just get a decent installation (or buy one already done) and you'll have no problems.

The only genuine issues are the practical ones as mentioned - loss of spare wheel and an extra 3 bolts to undo to move the tank to get to the battery but I am happy to trade those practical issues for the major fuel saving; being able to drive a 4.4 V8 X5 around as much as I like, worrying less about fuel now than I did when I had a 3l coupe, is an indescribable feeling. The loss of the spare is insignificant in context.

Needing a cheap to run runabout defeats the purpose of having a nice car - why spend your driving time in something rubbish knowing you have a decent car at home?

IanP · Post by **IanP** » Fri Oct 07, 2011 9:47 am

Of course, LPG emissions are lower as well, thats why the duty is lower on the fuel. And that is the reason I run my V8 on gas.

CondorX5 · Post by **CondorX5** » Fri Oct 07, 2011 11:00 am

Good for you mobilejo, luckily we don't all agree with one another or it would be a very boring world!!

The X5 and other magnificently engineered beasts were not engineered to run on LPG - fact. They run best on petrol - fact. My feeling is that if I can't afford the running costs of a V8, then I should buy something else, not mess around with the V8 to make it "cheap" to run. There are many many allegorical reports of catastrophic engine failures due to LPG conversions, so even if you get lucky and it doesn't happen to you, personally I would rather not try it. The day I can't afford to run my V8 as it should be run, I will take it off the road on a SORN until I can afford it, or I will buy I car whose running costs I can afford. And the fact that you convert to LPG certainly doesn't remove the need for servicing and maintenance of the car - you have that in addition to your LPG service, if you are looking after the X to manufacturer standards.

Each to their own, however......LPG conversions to otherwise beautiful cars make no sense to me, and I won't be messing about with this anytime soon. If I want Fiesta running prices, then that's what I'll buy......

shadrack · Post by **shadrack** » Fri Oct 07, 2011 11:34 am

Just to put my point in having owned an lpg and a diesel x5, they both cost about the same to run however the diesel is
Easier as its more readily available, however condorx5 I totally disagree with u as there will be alot more documented cases of engine failure on diesels due to various faults turbos etc but u would not dismiss al diesels! As for trying to run a v8 on a shoe string thats rubish u do whatever makes economic sense! I could have afforded to run my 3.0i lpg x5 on petrol but it was same price as a petrol wen I got it so why not save some money where u can, however I would always buy a pre done x5 as paying up to 3k for conversion doesnt realy make sense!

CondorX5 · Post by **CondorX5** » Fri Oct 07, 2011 7:18 pm

[quote=""shadrack""] however condorx5 I totally disagree with u as there will be alot more documented cases of engine failure on diesels due to various faults turbos etc but u would not dismiss al diesels! As for trying to run a v8 on a shoe string thats rubish u do whatever makes economic sense! I could have afforded to run my 3.0i lpg x5 on petrol but it was same price as a petrol wen I got it so why not save some money where u can, however I would always buy a pre done x5 as paying up to 3k for conversion doesnt realy make sense![/quote]

Nonsense. We all do whatever we want to do - what makes "economic sense" to you might be total rubbish to someone else. It doesn't make sense to me to mess up my V8, but that's only my opinion and its no odds to me who agrees or not, it is a valid opinion and we're all entitled to one. It obviously makes sense to others, as there's a whole industry built on it

You can "totally disagree" all you like - certainly won't change my mind

I didn't mention engine failure on diesels by the way - if you read my post you'll see I spoke about my Range Rover (the 4.6 V8) and premature enfine failure in RRs which were LPG converted, which is an extremely well-known fact. - not a diesel. I have absolutely no interest in diesels or their engine failures, other than to sympathise with friends on the forum if their diesel Xes give trouble

Can't quite see where I "dismissed all diesels" though, so I think you've got the wrong end of the stick! My company car is a diesel Kuga, its ok but give me my gorgeous petrol V8 anyday.......and not on LPG either! I part-exchanged my 3.0i for the 4.8is and am still delighted by the fab V8. I just wouldn't ruin it by converting it to LPG, nor would I buy a "converted" X5, but for those who like them, happy motoring.

We're all free to make (some) choices, luckily, now that Labour's nanny state dweebs are out of office

tombs · Post by **tombs** » Fri Oct 07, 2011 8:31 pm

LPG Conversions if installed properly are a good alternative. Condor, you talk about "facts" can you supply us with evidence of your claim? I'd be interested to read the report about these failures and why the LPG caused the failure.

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