I was driving down the road today and passed a petrol station. The sign said that petrol was 117.9ppl, diesel was 117.9ppl, but lpg was
65.9ppl; so that's almost half the price of the other two fuels.
I remember looking for a new car six or seven years ago. I saw a Ford Focus that had an LPG tank in the well where the spare tyre normally goes. I don't know where they put the spare tyre though (under the car?).
I didn't buy that car. At the time one of the reasons I walked away was that there were few lpg selling stations but I've noticed a few recently. Has lpg become more popular in the last six years? (I realise that car had a petrol tank but what was the point buying a gas car to use petrol 99% of the time).
Today I thought I would have a read of the maintenance group to look for posts about lpg. I found a couple recommending the fuel.lpg group but there doesn't seem to be much in there other than spam. Has that group died?
I seem to remember that one litre of lpg is not equivalent to one litre of petrol, but even so, with the massive price difference is lpg better than petrol and even diesel? I'm talking about buying a car that is already fitted with lpg, so the cost of a conversion would not be relevant here.
Regarding the petrol tanks: how big are they? Are they small and designed for emergency use when there is no gas or are they standard size?
Some of the old posts mentioned that duty would be increased on lpg, meaning the prices would meet those of petrol and diesel. These posts are dated 2004 and nothing seems to have happened yet. Will it?
That's more than half the price according to my calculator
In a small car you would probably leave it at home and carry one of these inflators instead. Vauxhall in their Vectras and Astras put a false floor over the tank and install the spare wheel on top.
Gas cars are manufactured as petrol cars and hence have a normal petrol tank. Location of filling points is relevant to the financial calculations as to how far off your normal journeys you must deviate in order to fill up.
Most active group is probably the Yahoo mailing list. Conversion is more routine now so fewer problems to discuss.
He caloric value of a litre of propane is a bit less (About 10%) than a litre of petrol. However the price difference more than compensates for that especially if you take out the conversion cost.
In the majority of cases the original petrol tank is left in situ. In some vehicles, notably Range Rovers, Discoverys and Jeeps the original petrol tank may be removed to make way for the gas tank and replaced with a small petrol tank for emergency use only.
A few years ago (about 2004) the then Chancellor announced that the fuel duty gap between petrol and LPG would be reduced by 1p per litre over a period of 5 years (I think). However with all the deferrals and changes to petrol duty it has been difficult to keep track of what is happening. This uncertainty has had a detrimental effect on the conversion industry.
I used to have LPG in two of my previous cars and would happily have again - blew the last one with a cylinder head gasket - never got round to having it sorted out as an expensive 3.0l - not the gas fault.
Gas stations - there was one in every town three years ago - bound to be better ratio now. Also in every town there was generally a gas place - calor and the like - and they generally do it a bit cheaper than petrol forecourts.
Generally the bigger body and bigger car engine the better the reason to change - I had a couple of old Vauxhall Carlton 3.0l 24v - so the 70l tank sat between the shocks in the back, taking up the space of a large bag of golf clubs, but still leaving a large useable boot space..you wouldn't want that in a metro. Also power to weight is important - a 3.0l heaving around a 70kg plus weight made little difference to performance, a metro is going to suffer.
As to cost - i worked out I averaged say 26 gallon on petrol, but the equivalent of say 44 (in money spent) on lpg - a cracking saving, with a slight loss of acceleration and top speed - again, unnoticeable on a big car - but could be a pain on a small engine one.
Servicing - well the gas side- people would just shake their head - but pretty reliable - it was just a glorified camping stove gubbins. But plugs and oil stayed cleaner much longer than on petrol.
Would I do it again - if I wanted a big petrol car- yes. If I wanted miles per gallon perfection I would have to do the maths as I see modern Diesel cars have probably better cost per mile - it might be better to go diesel than worry about the added complication of lpg. Thats prob why it hasn't taken off more. Small petrol car- not worth frigging about with.
It's worse than that. Energy content of lpg is about 77% that of petrol because you also have to take the density into account.
If I'm working it out right, a pound's worth of petrol will get you 72% as much energy as a pound's worth of lpg at the prices above. Depending whether your car likes it or not, that means you'll either do 100 miles for the cost of 72, or you'll just have 72% of the power.
If the conversion costs 1000 quid, you'll need to spend nearly 3 grand in fuel before breaking even. And that's ignoring any inconvenience.
IMX of driving a 1.6 Combo Van that is "factory fitted with LPG is, that i get around 30MPG around town/short 10 min journeys, and a bit better over a run. Though it falls of a cliff if i drive like a loon.
I live around the Bolton/Chorley area and get around the north and midlands plenty. Finding fuel has never been a problem, as i just fill it up whenever it is 1/4 or less whenever i see a station selling LPG. The difference with petrol is, around here at least LPG varies from 52p/Litre to 63p/Litre. ( and when i got the van about 2½ years ago it was 39p) so generaly i just make brim it whenever i am passing the cheapest if it is less than three quarters. I have never been one of them people who puts £3 of fuel in 10 times a week, i have always with all of my cars brimmed them and driven around till it is under a quarter and filled it again.
In addition to LPG i usually stick in £5 a month petrol too. In summer it probably doesnt use £5 a month, but in winter it uses more than £5 a month, so it balances out and there is always some in the tank if the LPG fails or runs out.
As for servicing, it is just normal service schedule for everything as normal (except the LPG) as with all my cars i generally change the oil every
6months/5-6000miles, as other posters have said it stays nice and clean longer. I change the plugs as per the handbook and they look like new when they come out, but then i have never driven a petrol car before so i wouldnt know the difference.
Since getting the car at 115k i have had the LPG system serviced twice, once at 120k when it wouldnt stay in gas mode, this was cured by a LPG service, where they changed all the filters and cleaned out various bits and bobs - Cost £165+VAT by a local specialist.
It picked up another fault at 160K when an injector failed causing a missfire, cost £170 service + £115 for a new KOLTEC injector + £30 for fitting and fiddling on the computer.
I have a feeling the the LPG guy i use is a bit like harrods prices, but he is the only one recommended for miles around.
I would have another LPG car in a flash, not sure about having one converted though!
Shit and derision mate, that's fekkin' extortionate!!!!!
Warrington Autogas (who have now moved from Warrington to Widnes -
formatting link
did my conversion and the last annual service they did for me - including new filters and stuff - was about £50. Having said that, I suppose it could be that yours is a Koltec system. They fitted an OMVL Dream XXI N system to my 3.0L V6 Auto and it's absolutely brilliant :o)
I know that you're looking to buy a car that's already LPG rather than pay for conversion yourself so I'd strongly advise that you have a good look around that forum to get a feel for it all first. The problem is that the car has to have the right system fitted. Not all systems are equal, nor are all installers.
I started by asking for recommendations for a good installer but quickly found out that it's not that simple because some installers are only qualified to fit one brand of system - and that may not be the best system for my car. For instance, I've got a 52-plate Nissan Maxima QX 3.0L V6 SE Plus Auto and when the engine is under heavy load, say, on a German autobahn, doing 120mph with a full payload and going uphill, that's when you really want it to be drinking cheap LPG instead of expensive petrol. Some systems can't cope with delivering the amount of LPG needed at that time and would switch back to petrol or even mix petrol and LPG to cope with it.
There's an installer about 7 miles from me and by all accounts, he's a master craftsman in LPG installations. His work is more like a piece of art; very clean, very tidy, and a joy to behold - but he's only qualified to install Tartarini systems. When I asked if it would cope with the above scenario without changing back to petrol, he didn't know, so I went about 40 miles away to Warrington Autogas (who have now moved from Warrington to Widnes
formatting link
They assured me that an OMVL Dream XXI N system would cope easily and have oomph to spare, so I went with them. I've now covered 27,000 miles in the 20 months since conversion and I'm one extremely happy bunny :o)
So, even though you're not looking to have the conversion done yourself, make sure that whoever did it, did it right.
Rip off !! (see end of post) Shell and many other stations, out of town on trunk roads (DC) charge M-way prices. It's quite easy to find just off Trunk/M-way superstores with 24hr LPG, Sainsburys Watford, ADSA Bristol.
I'll show my calc (confirms yours)
Cars don't condense the water vapour in the cylinder so LHV is needed.
formatting link
LPG Liquid density 0.51 Kg/L Vaporized 46.3 MJ/kg. so that's 23.6 MJ/L @ 65.9ppl = 35.8 MJ/£
Petrol density 0.72 Kg/L
42.5 MJ/kg so that's 30.6 MJ/L @ £1.179/L = 25.9 MJ/£
1.38 x the energy/£ compared to petrol, or LPG is 72% of the cost of petrol. V-power, BP-ultimate, Tesco 100RON will cost even more (cheapest within 20 miles of me is 123.9p/l and many are 126.9 p/L) but has lower octane than LPG.
1.13 x the energy/£ compared to Diesel, or LPG is 87% of the cost of Diesel. Diesel gives 1.2 x the energy of petrol and 83% of the cost. But Diesel is more efficient at part load as they run lean and un-throttled so difference to petrol is wider and narrows the gap on LPG. Diesel cars cost more, often when new as much more as a LPG conversion to a new petrol car. So at these prices it's more down to convience of supply and choice of engine between SI or CI response than cost.
The LPG vapour displaces about 4% more inlet air than petrol, so about
4% power loss at wide open throttle. The throttle needs to be opened a bit more at part load, so may feel a bit less responsive on LPG. The complete lack of soot in the exhaust (and engine oil) indicates it has slightly better efficiency than petrol (soot is un-burnt fuel) as does much lower un-burnt HC. This claws back a bit of the volumetric loss. It will allow better timing and higher boost for more power than petrol with a boosted engine. N/A engines would need an increase in compression ratio and removal of the petrol system to properly take advantage of the high octane. Going from 96 RON at 9:1 to 108 RON with
12:0 gives 3% points increase in efficiency. Or assuming efficiency is about 30% > 33% is around 10% gain.
Is anyone really stupid enough to use E85 for everyday use in the UK? As it's only a few p/L cheaper, if at all and consumption is way higher (about 20%) it makes being "green" very expensive. Though as it's still much cheaper than VP race fuel, it's great if you have a CCXR, that makes 200bhp more on E85. It's tuners fuel of choice for Ireland and Sweden.
There is no LPG in Burton on Trent and petrol prices are sky high. Shell undertook to set prices at their service station opposite to Tesco at 1p/L lower (I was in there when the manger got the call to confirm it). Tesco figured it out, stopped competing and put prices up, Shell tracked them back up. Prices are so high that out of town trunk road services are cheaper.
Morrisons Burton 3.79 miles 115.9p Jet Brobot Willington Services A38 Nth & Sth 4.62 miles 115.9p Shell (not Tesco) Burton 2.06 miles 116.9p Esso Hatton Service Station 2.87 miles 116.9p (go 13 miles to Derby and there's 9 at 114.9p, or Swadlincote 7.8miles and there are 3 at 113.9p)
Nearest LPG is 13 miles from me. At 65.9p/L you will clearly have been RIPPED OFF. Asda Derby 16.71 miles 54.9p Total Fradley Service Area A38 North 12.57 miles 57.9p Shell Allestree Derby 13.84 miles 58.9p Total Appleby Magna (M42 junction) 13.01 miles 60.9p
@ 55ppl = 42.9 MJ/£, 60% of cost of petrol and 72% of cost of Diesel.
If a convenient cheap supply is there then LPG beats Diesel by a long way. The ASDA Derby one is only 3 miles from where I work but it's 3 miles the wrong way. Would cost me 80p to go fill up and the others are actually even further out of "my way" so longer round trip. Spare wheel tanks hold little more than 40L, if that, so 2p/L premium. Better get a big tank on a trailer and fill that once a month or take two 13Kg bottles on the back seats evey week, get a pump and double the range.
Finally whoever the bod is in No11 they can't put road fuel duty on domestic propane and there's no difference between UK domestic propane the UK LPG. 19Kg (37L) bottles are around 70p/L at the moment, bigger will be cheaper like 47Kg (92L) is 65p/L, under 19Kg are not at all competitive.
I had a Ford Scorpio 2.3 litre engine that I converted to run on Lpg in
2001 and I finally changed it last year and it's still going strong.
I did over 80,000 miles after I converted it to run on LPG, I had a few hicups whilst runing on LPG, most notable when the weather was cold and damp it had the habbit of blowing out a breather plug in the inlet manifold and stalling the engine. The first couple of times it did this was a problem, but after that I got used to it and it was a couple of seconds to push it back in.
The most important part was that it cost about £1200 to convert and I showed a saving of £5400 on the time that I had it.
And as said above the car is still going strong with its new owner and its still running on LPG.
MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.