Is a V8 on LPG really as 'economical' as a diesel?

OK, we all know how everyone states that LPG costs as little to run as a diesel, etc etc, but is it actually true?

Here's the scenario - I currently run a BMW 330Ci which returns around 26/27mpg on a mixed drive to and from work each day and over 30mpg on a run.

I have decided to sell the BMW and get either a P38 Range Rover or a Discovery II.

I have been looking for a diesel (so either a DSE or TD5 ES) as I need reasonable fuel economy, and both should return similar figures to what I currently get from the BMW.

What I want to know is, in the real world, would a 4.6 V8 P38 or a 4.0 V8 Disco II on LPG be as efficient (in terms of £) as a diesel? It currently costs me about £75 to fill up the BMW, from which I get 320 miles to a tank in normal use, based on around £1.36 a litre. Has anoyne got any comparable diesel and LPG figures for me?

Because lets be honest, a V8 is ALWAYS preferrably to a diesel, but if in reality the best an LPG'd V8 manages is an equivalent 20mpg then I'll go for the dirty derv ;-)

Cheers!

On a mixed drive I get around 15mpg on LPG and around 18mpg on petrol.

If you take 25mpg on diesel as the ball park....

Diesel: £1.36 x 4.54 = £6.17 per gallon = £0.25 per mile

LPG: £0.80 x 4.54 = £3.63 per gallon = £0.24 per mile

Petrol: £1.35 x 4.54 = £6.13 per gallon = £0.34 per mile

Personally though, I think you'll be lucky to get 25mpg on diesel, so LPG definitely wins

Well my d2 v8 on lpg is proving cheaper to run than my d3 tdv6 was!

I have owned both and there is not a lot in it especially if you consider how far you may have to travel to get the lpg.If the lpg is slightly cheaper that is outweighed by the convenience of diesel as in buy it anywhere,easier to get serviced ,not restricted where you can take it (euorotunnel etc),easier to insure than lpg and of course not having resticted boot space due to loosing spare wheel well:
OH AND PLUS THE TWO GRAND OR SO TO CONVERT IT

not in a v8 compared to a 2.5 diesel it aint

I average 16 MPG on LPG that is mixed town and main a road/m way. And I generally drive fairly quick. no soft starts and 80odd on the dual carrigeways and motor ways.
The maths says it all really. Pound for pound LPG can work out slightly cheaper than diesel. And seeing as diesel seems to be going up faster than petrol or gas aswell it seems better to run LPG. Although it would take a long to time to recoup the cost of fitting the system. If you can get a converted one for good money than that would be better

Go for the diesel , as said above takes a long time to recoup the money spent on a conversion unless you get one already done, but must be a good conversion as they can play up and easily go wrong if not installed well or if cheap parts are used (a lot of the LPG kits come from Poland) to fill up on LPG fuel stations are far and few between, space lost due to tank sizes and servicing of the LPG system every year on top of servicing the v8, but then I must admit I did love my old 4.6 p38 with gas conversion, having a v8 under the hood is a good feeling but did cost a few bob and wasn't really worth sod all when I sold it, in all honesty go for the diesel

Theres a lot of talk about loosing boot space. I had twin tanks underneath the car so no loss of space. Wish I had the tanks swapped to my other RRC. () litre tank in the boot DOES take up space. As for having a spare wheel tank. WHY? Where you gonna stick your spare wheel? HAve it floating around the boot unsecured? Now that is a tragidy waiting to happen.

DIESEL no doubt ,

i can get over 30mpg out of my 90 even towing a caravan...

Jon14 said:

On a mixed drive I get around 15mpg on LPG and around 18mpg on petrol.

If you take 25mpg on diesel as the ball park....

Diesel: £1.36 x 4.54 = £6.17 per gallon = £0.25 per mile

LPG: £0.80 x 4.54 = £3.63 per gallon = £0.24 per mile

Petrol: £1.35 x 4.54 = £6.13 per gallon = £0.34 per mile

Personally though, I think you'll be lucky to get 25mpg on diesel, so LPG definitely wins

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Depends on which model you're talking about though. With a Defender, it's 12mpg for a V8 on LPG, and 30+mpg for a Tdi.

This isn't even taking into account the massive savings you can get running a diesel on SVO - I pay between 50p and £1 per litre for my fuel

i get 32 on a 200tdi disco.... engine servicing is an oil and filter change.... havnt spent anything else on the engine in 5 years

TDI every time it's a no brainer. Reliable, cheap to buyand run on veg oil without any daft unnecessary conversions.

And if we're bringing power/driveability into the equation, I would happily pit my 200 against a 3.5, especially now after the injection pump tweaks, thing flies!

May have missed something guys.. he's mentioning the P38 and the D2.. Neither had the TDI :doh:

Our 4ltr disco is doing about 16 to the gallon average running on lpg, on a motorway run its been above 20mpg... Locally about 73p for lpg vs about £1.44 for doozel.. so call it about 1/2 price locally, 16mpg at about 1/2 price works roughly equivilent to 32 to the gallon. As for lost boot space, underslung is wonderful, gas tanks on this disco are tucked right up out of the way and are protected off road by the tow plough, not under the sills like normal... Only down side is its had the petrol tank taken off to put the tanks there, and it only has an iccle 40ltr reserve!!

let me think £2000 = how many galons @ 0.01 per ltr now calculate how long it will take to recoup the outlay

Factor in though that V8's have lower residuals than the diesels, so cheaper to buy in the first place

I've got a Fiesta diesel that I run everyday, so quite happy to have the V8 to fire up at the weekends

Langers said:

And if we're bringing power/driveability into the equation, I would happily pit my 200 against a 3.5, especially now after the injection pump tweaks, thing flies!

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Think your 200tdi is as quick as a v8? Don't be silly!!

Ok everyone on here is worried about MPG. how about the true cost of running a lpg system
the cost of the system and the insulation costs
additional maintenance cost
additional cost of repair parts
inconvenience of filling up and driving restriction of lpg
loss of cargo space
tune up for v8 motor

and base this over a 5year period what are the true savings
a diesel wins hands down

compleatly agree
if you are planning on keeping your car for 60 years by which time you will have recouped the cost and maybe if we have not run out of petrol and deisel you will be able to sell it for 2 million

CAVEAT EMPTOR
its your money

I get 30mpg straight and no service costs.

I have run all types of landy and the TDi will allways be the cheapest to run.