HI all, we ran out of LPG the other day. What with the snow etc, our local garages didn't have any, so we had to run our 4.4 BMW M6-whatever car on petrol. I put £40 of Tesco Momentum in, the range on the computer said it would do 212 miles before running out (may have been a little more, it doesn't matter and the computer would have been the same if I'd have put normal Tesco fuel in as it's not to know). I got some LPG later on and filled up for just over £53 (not quite 80 litres for a 100 litre tank, I think about 76 litres and it was 67p per litre) and we get around 200-250 miles out of that. It's got me thinking.....is it actually worth running it on LPG or is my maths completely out?

I think u have to know what mileage you achieved on the petrol.

If u had been running lpg prior to filling up with petrol, then presumably the Range calculated after your petrol top up was calculated with the LPG usage prior. so 212 miles may be misleading

Maybe worth testing again, by doing two tanks in succession of lpg and petrol and seeing how far you get on as near as dam it full tanks, assuming the same driving conditions. Filters are in fact so good that in certain circumstances, when the ambient air is already polluted, a diesel car will tend to extract more particles from the air than it emits. Emissions Analytics worked with........etc etc

He who dies with the most toys wins...

Dont go buy what the computer says its a guesstimate only , should achieve an approximate saving of 40% when running lpg after the conversion has paid for itself , if you bought it already converted your saving straightaway

By poxy autocorrect

One of our P38's had a sequential multi point kit on it when I bought it so I've been running it on LPG.

I noticed when at Asda the other night that LPG there was 52p a litre so yours is expensive!

Usually you loose about 10% of your economy on LPG because LPG doesn't have as high a calorific value as Petrol, so on a run if you get 20mpg on Petrol you might get 18mpg on LPG.

However, as LPG (in my case) is 52p a litre versus 116p a litre, the fuel you're buying is less then half the price which more then makes up for the difference in economy.

Running locally in the P38 on Petrol I got 280 ish miles from a full tank of fuel which was £100 worth of Petrol, on a full tank of LPG which cost me about 39 quid, I get approximately 200 - 225 miles depending on the type of driving I'm doing.

2 tanks of petrol would cost me £200 and get me a range of 560 miles, to get the same range on LPG it'd take approximately 2.5 tanks of LPG which works out at roughly £100 which is half price.

LPG systems do need servicing, reducers loose their efficiency, filters get blocked, so there's a chance that yours isn't running as well as it should on LPG and is consuming more then it should.

Financially, given the limited mileage I do, I wouldn't convert a car to LPG myself, however, on a P38 that I didn't pay an awful lot for, it's nice to see the litres going up quicker then the £'s

I reckon that my P38 which has the 4.6 Petrol in it costs the equivalent of about 40mpg on a run now.

David. 2002 4.6 Vogue SE - Alveston Red with Lightstone Leather
2012 Range Rover 5.0 SC Autobiography in Indus Silver with Jet/Ivory Interior
2012 Range Rover 4.4 TDV8 Autobiography in Baltic Blue with Sand Interior
2013 Range Rover Sport SDV6 HSE Black Edition in Santorini Black with Ebony Interior

I run on lpg my computer says I get 19mpg but when worked out tank to tank it’s closer to 13mpg. Mine dose the same when I fill up with petrol but you won’t get near that many miles.

Definitely worth it...

Used to average 17.88 on petrol before the LPG conversion.

Average on LPG has been 14.6, and since Aug last year have paid average of £0.588/litre, which includes topping up with unleaded every now and then.

This means I get the [cost] equivalent of 30.8mpg when running on LPG, which has saved me £7,215.19 in fuel costs since getting the conversion done in June 2012 [since done 54,000 miles].

Even taking the cost of conversion into account and servicing, I've saved about £5k - about £1,000 every 10,000 miles. I reckon that conversion payback time is about 17,000 miles, and it's cheaper converting a petrol L322 to run on LPG than a diesel after 35,000 miles. Current:
- 2017 L405 3.0 V6 Autobiography
Sold:
- 2013 L405 4.4 TDV8 Vogue
- 2004 L322 4.4 Vogue (BRC LPG)
- 2002 L322 4.4 HSE (having fixed timing chain guides)
- 2000 P38 4.6 Vogue (BRC LPG)
- 1981 2-door In-Vogue
- 1980 Ex-Army SIII LWB
- 1976 SIII LWB
- 1968 SIIA
Stripped for parts:
- 2003 L322 4.4 Vogue

If you work it out as Pence per mile, then you get a fair comparison across all fuel types and car models.

My LPG cost in my 2004 BMW engined 4.4 V8 Petrol is c. 17-19 p per mile. Petrol was c.30-35p per mile (18MPG avge). Diesel in TDV8 4.4 (at 28 MPG avge) is 20p per mile.

So on LPG you are getting a better MPG than any other model L322!!

(all prices costed with Diesel at £1.22/L, petrol at £1.20/L and LPG at 0.55p/L)

I filled up today in Walsall @ 50ppl and went up the M6 to Bolton and then Blackburn and sat at 70mph (and 50 in the 10 miles or so roadworks) with some town driving returning via the same LPG station and I did 225.5 miles using 61.4 litres. This works out to be 40mpg pro rata or 13.6ppm. (£0.50ppl vs £1.20ppl) so I’m pleased with that.

I hope this helps the debate?

Hi all and thanks for the replies. I was just going on the range the on-board computer was telling me we'd get from the petrol I put in against what we get from a tankful of LPG (and her ladyship driving the massive 1/3 mile to work).
I also do the sums from time to time and it usually ranges from the equivalent to high 20s to low to mid 40s depending on where we buy it, normally hovering around the 30 mpg mark which I can live with. (I did buy in Birmingham a couple of years ago. Is it Cuckoo Lane, Nechels, Birmingham LPG? I think it was 36 ppl at the time. Anyway, it worked out as the equivalent to over 50 mpg).
We're not blessed with an Asda or Morrisons selling LPG nearby, so our prices are a little higher.
Cheers

I run a 4.2 V8 supercharged RR and I would love to have LPG at the prices you quote. I live in North Devon and there is only one station (BP) that sells LPG and it is 79p litre. When I go online to check prices out of curiousity it is always the most expensive I can find. Almost worth driving to Plymouth or Exeter (an hour each way) where you can get it for less than 50p!

The best site I’ve found for finding LPG sites and prices is https://www.filllpg.co.uk/ Current:
- 2017 L405 3.0 V6 Autobiography
Sold:
- 2013 L405 4.4 TDV8 Vogue
- 2004 L322 4.4 Vogue (BRC LPG)
- 2002 L322 4.4 HSE (having fixed timing chain guides)
- 2000 P38 4.6 Vogue (BRC LPG)
- 1981 2-door In-Vogue
- 1980 Ex-Army SIII LWB
- 1976 SIII LWB
- 1968 SIIA
Stripped for parts:
- 2003 L322 4.4 Vogue

I previously had a Grand Jeep Cherokee on LPG and hit continuous problems including i.e. car acting as a kangaroo, do the current LPG systems run smoothly on range rover or is that still underlying issues?

At the moment I'm considering 4.4. tdv8, 4.2 SC or maybe a 5.0

Got lpg on mine about 20k miles ago
No real issues after some initial tweaks and equipment upgrade after the initial install.
It all hinges on the experience of the installer and his mapping capabilities.
If I had to get a new install I'd go to simon at lpgc.co.uk

Thanks dingg1. You got 4.2, 4,4 or the 5.0 ?