This is something I have pondered on and off for years but thought I'd ask the collective for your experience.
Many 4x4's have LPG conversions but I wondered whether they consume the same amout of LPG as they do petrol per mile on average?
I've got a Chevy Astro Day Van running on LPG. the MPG running on LPG is worse than when it runs on petrol, you make the savings because its much cheaper
a litre of lpg has less energy than a litre of petrol. never had an lpg car but from what ive read the mpg goes down by about 10-15%, but the fuel
cost is nearly half. ive never been convinced its cheaper than a good diesel car, specially as most have to warm up on petrol power. Does make an old
4litre jaguar very tempting though
Also I think the range on LPG is typically quite poor. Obviously you've still got the petrol tank, but you can't do a 300 mile journey
purely on LPG without filling up (depends on the size of the LPG tank, obviously).
[Edited on 5/12/11 by rodgling]
Had use of a few LPG cars and known some more. Straight 6 BM on it runs about 10-15% down on mpg (not surprising considering lower power density of the fuel) and has a smidge less power, this is with a nice injected system. Takes 30-60 seconds to switch over to LPG. Used a liquid lpg injected van (astra IIRC) and that was shockingly poor on power but had about the same 10% drop in economy on LPG. But even motorqay services sell LPG at 78p/litre, so it's WAY cheaper than a diesel *of the same performance* I think.
I've run 210k in a civic 1.6LS on LPG and about 100k in a subaru legacy 2.5(non turbo).
The honda felt less torqey, and used about 20% more gas by volume than on petrol.
The subaru felt identical to drive, and returned almost identical miles per litre. The problem I had on the subaru (eventually) was the oil seal rings
on the pistons failed (compression was still good). I've since heard from a couple of people that this can be a problem on subarus runing LPG,
but I guess not all that common, and probably stilll a lot cheaper if you do it on a 2.0 where the engines can be found in scrapyards(2.5s are like
hens teeth).
Regards
Hugh
In the UK LPG is propane and has 15% less energy content per litre than petrol, fuel consumption in MPG 10 to 20% higher also engine output at
full throtlle is 8 to 15% down ---- roughly the same effect as dropping down one engine size eg replace a 2 litre with an 1.8. In practice
the performance difference dosen't matter because on injected engines you can switch instantly back to petrol for extra umph.
The drop in power output is because LPG is a gas and takes more of the intake charge than petrol mist, however LPG has a higher octane ratio and
this can be taken adavantage with electronic gubbins to advance the ignition on LPG.
The next generation injection systems are liquid injection and any power loss will be a thing of the past.
[Edited on 5/12/11 by britishtrident]
quote:
The honda felt less torqey
The Stag website Stag is pretty good for info on their systems in the downloads section you will find manuals.
Also check out http://autogas-lpg.co.uk/conversion-kit/85-conversion-kit-ac-stag-4.html
and http://www.tinleytech.co.uk/
I have run 200k miles in 4.6HSE P38 range rovers, first had an early venturi system which cost power, the second a full sequential injection
system.
Also XK8 70,000 miles with a mixed system, 5% petrol with 95% gas, these have soft valves.
Do not worry about MPG, you will go nearly twice as far for the same money.
On 14,000 miles per year I save £1000 in fuel costs.
I ran a 4.0ltr discovery for a few years before getting a newer TD5, the v8 was a much smoother and more powerfull drive with slightly better mpg as
it would range from 15 to 18mpg compared to the TD5 getting 28 to 32mpg.
If I had to make the choice again I would go for the LPG option.
There is also the added choice of a diesel / LPG option that is getting a little more populal!!!
quote:
Originally posted by kevmcdo
I ran a 4.0ltr discovery for a few years before getting a newer TD5, the v8 was a much smoother and more powerfull drive with slightly better mpg as it would range from 15 to 18mpg compared to the TD5 getting 28 to 32mpg.
If I had to make the choice again I would go for the LPG option.
There is also the added choice of a diesel / LPG option that is getting a little more populal!!!
ISTR hearing a few months back that doing new LPG conversions on diesels is under a temporary ban because no EU regs exist yet.
[Edited on 5/12/11 by britishtrident]
hi there, i have got a 4.0litre jeep which i just got the converted to lpg (older type system) it has a 100litre gas tank and does take some power
and achieves around the same mpg as i drive it not easier, i do not use the sports mode any more, and barley use the kick down
it is good now, before it was killing in fuel cost
stu
There are quite a few TD5's kicking around with lpg on them with the added bonus that they get a little performance boost with them too, I was not aware of a ban on new installs though which would be a problem when it comes to insurance.
Wow
I didn't expect such a response.
You see lots of statements in adverts of lpg converts and I've always been sceptical as regards the achievable savings.
I had no idea about diesel lpg's though
i have been running lpg converted vw t25 camper(2) for 7 years.
they run much better on lpg
i'm now running a 1983 vw t25 camper on lpg and i never use petrol ever, it does about 19-23mpg on gas.
all my other t25 did around 20-25 on petrol,
quote:
Originally posted by kevmcdo
There are quite a few TD5's kicking around with lpg on them with the added bonus that they get a little performance boost with them too, I was not aware of a ban on new installs though which would be a problem when it comes to insurance.
quote:
Originally posted by kendo
Wow
I didn't expect such a response.
You see lots of statements in adverts of lpg converts and I've always been sceptical as regards the achievable savings.
I had no idea about diesel lpg's though