LPG or Diesel? (long)
 

I'll hopefully be on the lookout for a replacement car in January.

The car must do at the very least 40mpg (real, not manufacturers combined figures) so I suppose I'm really looking at 45mpg+ official figures.

Anyway, a Toyota Priius(sp) is out of the question as it's too expensive, so I'm left with LPG and diesel. Car must be a decent size too, so that puts out petrol supermini's.

Am I best to go for LPG or diesel? What are the disadvantages / advantages?

I've got a Diesel now (Skoda Superb PD130) which is averaging 45mpg which I think is pretty good for such a big car. However, that's going back in late January, and I'll be downtrading to a car worth about £3k.

Do diesel's need more frequent servicing? (Skoda has variable servicing - not had a service yet) £3k will probably get me a 1999 at the newest, so we won't be talking these newer designed diesels.

What should I look out for on LPG's?

Anyone know what mpg for an LPG is compared to petrol? Gather you get less mpg out of LPG than petrol - is there a figure I could use to calculate (80%?)

How do I know who a professional LPG fitter is?

What size tank should I get? I've heard of the one's that fit in the spare tyre well, but that's not much good if the tank is tiny.

If I go LPG, it'll be a car with the gas already fitted. Otherwise I'd be looking at a £1500 car with £1500 to install LPG.

I'd love to get a big comfy barge - Saab / BMW 5 / Merc with LPG, but they're too rare or too expensive. Expensive to run too, which kinda defeats the object of getting a car that's cheap on the juice.

Going of a bit now from the thread title - but cars I've considered thus far (browsing Auto Trader - not actually looking yet!) are:

Citroen Xantia Estate TD
Peugeot 406 TD Estate
Ford Mondeo TD Hatch/Estate
Omega Estate TD
Volvo V40 TD
Toyota Avensis Estate TD
VW PAssat Estate TD
VW Golf Estate TD

Some of the LPG's I've seen on Ebay:
Suburu Legacy Estate
Mondeo's
Omega's
Merc 560 SEC (love one, but doubt it'd make 30 mpg equivalent lpg : petrol)


Any of the car's I've listed to be avoided? Any glaring omissions?

Just want a decent sized car (hatch/estate) that'll do 40mpg+ and won't cost the earth to maintain. I'd like it to be fast too, but I realise at £3k I'll have to make compromises!

I have an LPG MX5 (honest)(it's also for sale)

The thing about LPG is thst it doesn't give you better fuel econ, the fuel is just cheaper and cleaner.

I'd be tempted to go the diesel route ... LPG is always an aftermarket fit, and the reliability on this could be questionable.

With a diesel, what you see is more likely to be what you get. If you can get a car with a VAG TDi 110bhp motor, these are pretty punchy, give 45+ mpg and are easily tuned to a reliable 130+bhp and 230 lb-ft for £300 by Jabbasport or Revo. They're also proven to do the miles with normal servicing. This gives you the choice of Golf Mark 3 or 4, Jetta / Bora, Audi A4 / A6, Passat or pre-facelift Octavias.

I run an LPG legacy, great idea and at 39p per litre its certainly cheap. There are a few different lpg systems out there and i would certainly say the price you pay really does matter. I have an SGI sequential sysyem on my car (£2500) and you would not notice the difference in performance between the two fuels. With the cheaper systems the car will drive different :(

You will loose a few MPG, I average 29MPG on Petrol and 26MPG on LPG. Another problem you will find is the availability of the fuel but if you drive a few miles like me then that wont be a problem as there are plenty of LPG stations on motorways and other main roads.

Overall i would say its a great idea and you dont have to drive round a smelly tractor :D

PS Legacy is for sale ;)

I have looked at this closely over the years.

Conclusion i came to was a decent TDI would beat LPG hands down for cost.

You could get a very late model Mk 3 Golf TDI estate for £3k or less. It will give you 55mpg and very cheap servicing and parts coutesay of Euro car parts.

396HDI is similar but the VW tdi engine is the best.

I have one thats now down 181,000 miles and is still going very very strong.

Only thing i have ever done apart from regular servcing and maintanance was to put a new starter motor in it.

The negatives of derv is significantly out weight by the positives. Cost being the biggest.

Its noisy but its a good solid car, and surprisingly nippy too.

My wife has a Civic vtec-e but it only gets about 35 mpg and its ment to the the ecconomical version.

Go derv.

Do like the idea of a Golf - we had one a couple of years ago - cost us virtually nothing to run. Probably the smallest car I'd consider though.

I'll check out the Scoobynet classifieds to see what's about.

There is a petrol station near my commute that sells LPG 29p/litre. Almost 1/3 the cost of diesel! So if you get a car that does 25MPG on LPG then it would be equivalent cost wise to 75 MPG on a diesel - there ain't many that do that :eek:

The other thing about LPG is that you don't get the same wear rate as petrol due to it mixing better (it is naturally a gas rather than petrol which is sort of vapourised but really remains a liquid) and you don't have to enrich it from cold so less bore-wash. The oil gets far less contaminated as well so sticking to the usual 10K oil change intervals should fare much better than petrol at 10K.

Personally I'd love a nice big car with a decent engine on LPG, you get far more car for your money than the equivalent diesel, and if it's an older car the diesel will most likely be rough and noisy. I've seen a few Omega MV6 with sequential LPG conversion going for around £2k - 207BHP from a nice sounding V6 engine which should easily see 25MPG on a run ~= 75MPG in cost terms compared to diesel. Loads of toys on these too, HID lights, dual climate control, 17" wheels, traction control, electric everything etc etc. And RWD with great handling for a big car, if I see another I'm very tempted to take the plunge to replace my Audi as a runaround.

PS The only ones to watch for with LPG are Zetec engined Fords, some of them have soft valve seats which can't handle the combustion temps and wear out after around 30K. Ford basically made the head *just* hard enough for unleaded, but there's a replacement head available that some of the pre-converted cars may have had fitted.

Our survey says ...Null points...

Its not quite as straight forward as that.

Derv is 80.9per liter or £3.64 per gallon
LPG is 29.9per liter or £1.34 per gallon

TDI will do 55mpg easy

LPG will do 25mpg at best( assuming its not bigger than 1.6 engine)

1 mile in the tdi will cost 6.6p

1 mile in the LPG will cost 5.4p

Add in the conversion cost say £1000 over lets say 50,000 miles. = 2p per mile

Oh look tdi cost 6.6p per mile
lpg cost 7.4p per mile

A bit simplistic but LPG is simply not as cheap as a good diesel, on top of the supply issues and the fact it will take up storage space either in the boot or with no spare tyre. Small LPG tank range too, whci mean you will run on petrol more often that you think. All adds up. Not only that but the gorernment are increasing duty on LPG faster than other fuels.

p.s. 29p/ l is very cheap usually its 36p / l which swings it even more in favour of the derv.

Happy hunting.

I run a 4.6 HSI Range Rover.

£80 to fill it with Unleaded, gets you 220 miles.

£29 to fill with LPG, gets you 200 miles.

I put it on the rolloing road at PE, made 280bhp on unleaded, and 270bhp on LPG.

Conversion was £1,800

Before this I had a diesel Golf TDi 115 bhp.

To be honest I'd go back to the golf now, even though this has TV, Xbox, Sat Nav, electric everything. It's just a big tank, and I want my golf back!

In the gold I fill up with £42, gets me 500 miles.

Yes Please.

My mate got an Astra 1.8 (2000 model) converted to LPG a few years back and although it is cheaper to run on LPG (obviously), it doesnt run very well on it. Stalls quite often, and runs better/faster on petrol.

Another mate has a Volvo S80 LPG and thats a factory conversion, so its better - but noticably slower on gas, and duel tanks mean the range on LPG is poor. These depreciate like mad, so you might get an early one of these for 3-4k.

VAG diesel would be my choice, however you pay a big premium for a TDi, and unless you do 20k miles/year its debatable whether its worth the extra.

:eek: Cant be that bad surely? Thats just over 10 mpg assuming fuel at 83.9/litre!

Yep, thats bout right!!!! :eek: :eek:

Factor in the fact that you're buying second-hand.... factor in that an LPG converted car on the used market fetches almost no premium over a non-converted car.... factor in the fact that diesels always always cost more for the equivalent model.

So the LPG model looks even more appealing using your logic. For example the Omega 3.0 V6 I quoted earlier with full professionally installed sequential injection LPG kit, costs around £2k - much the same as normal petrol models. And if it's done correctly (ignition advance etc) there is almost no noticable performance difference. So you can pay £2k for the 3.0 V6 LPG converted Omega which is quicker, more refined, nicer sounding and better specced than the closest equivalent 2.5TD model which would go for around £2.5-3k. Hmmmm difficult choice I think not, unless you're nowhere near an LPG outlet or absolutely need all the boot space.

If you're buying new or buying a petrol car to convert yourself, then yes you need to do a lot of miles to recoup the cost and maybe diesel is a better choice. But if you can find the car you want, buying pre-converted makes a lot of sense, add to that you can tell before buying how well it performs compared to petrol (flick the switch while driving, very simple).

I've seen quite a few 3.0 V6 Omegas specially commisioned by traffic police and converted with LPG. I'd imagine they run on it more or less all the time (to save costs), and some of them appear on the used market with 200K+ miles on them, still running perfectly well on LPG. So the performance and reliability can't be that bad, and I haven't seen many 2.5TD Omegas doing traffic duties.

I run a nissan 200 on lpg which was the best thing I could of done 4 years ago. Saved me a small fortune in fuel

I also just bought a 330 diesel which is a great easy car to drive but prefer the nissan for driving enjoyment and economy :D

PMSL so you think an Omega 3.0l V6 LPG will get 25mpg... What planet are you living on.

Stop comparing it with a car with a piss poor diesel engine.

HDI or TDI will do easy >50mpg all day every day, i get 600mile out a tank on my golf. LPG is NEVER going to compete with that. And when i come to sell my diesel i know someone will want to buy it, as you say who wants to buy an LPG converted car...

Case proven m'ludd

Merry Christmas...

my dad drives a 2.4L d5 volvo v70 diesel, he gets 48mpg average per tank. the volvo is huge mind you but it does have 170bhp. good fun to drive to, bit of wolf in sheeps clothing having 170bhp but looking like a barge

Easy 25MPG on the M-way. My dad recently bought a 330Ci and he's averaging 31/32 MPG, mostly M-way but that includes some town driving too. OK he's a sensible driver but it proves the point that a 3.0 Omega should get 25MPG quite easily if it's mostly M-way miles and you don't cane it.

Funnily enough he's also had a Mondeo 2.0 TDCi and a Vectra 2.2 DTi, both modern common-rail electronically controlled diesels. Both averaged around 47MPG, so you're "easy >50MPG" seems to have eluded these cars... Hmm maybe it's because they're such high performance 130BHP beasts lol

LPG can't compete on range, but on cost it more than competes. Comapre it with any diesel you like, but show me a diesel that produces over 200BHP, costs the equivalent of doing 60+ MPG and can be bought in good condition for under 2k and I'll put my name down.

And as for the last comment about someone will want to buy it, that's exactly why an LPG car makes more financial sense when you want a cheap runaround... lower demand means you get much more car for the same money, who gives a toss what others find more desirable and use the fact to your advantage rather than following the crowd. Once that cloud of black diesel smoke clears you may be able to see that ;)

Merry christmas :D

What are you on about.

re read the first post and mabe alter your spec slightly. Have you been on the night nurse again?

>50mpg is easy meat for a golf tdi.

If you want to drive fast buy a Porsche, if you want ecconomy buy a diesel.....

Oh just like me.....

Cheers.. hic...Merely Chrsbmass Hic...

So if you want economy it has to be a 106 Diesel or similar.... why spend all that extra on a less economical golf? Your logic is sorely flawed which explains why we have so many cars on the road other than porsches for the performance freaks and diesels for the cheapskates. I guess you've never considered the terms "compromise" or "trade-off".

I always love a poster with blinkers who resorts to personal insults at the merest suggestion of someone not wholehartedly agreeing with his priceless advice.

I would like a high performance car, but realistically, for £3k I think I'll struggle to find one. Even if I find one for the price, it'll be more expensive to run - higher servicing / parts / tyres.

I will be doing 18,000 miles per year just going to work and back - so I'd have thought 25k plus p.a. Any LPG car I consider will already be converted.

The LPG cars I'm considering is stuff like 2.0 Mondeo's - I'd expect them to average 30mpg to start with. Say 27mpg on LPG - even at half the price of petrol, that'd give me 54mpg equivalent.

That would make sense. It depends on what the pricing is like where you stay, but like I said on my commute the LPG is almost 1/3 the price of diesel (and I've heard of it cheaper in some parts of England, remember duty is something rediculously low like 6p/litre on LPG whereas on diesel it's more like 50p/litre on top of which there's 17.5% VAT).

Just don't let our Golf 110 TDI loving friend know about your scandalous thoughts, anyone considering such a move surely but be under the influence of some intoxicating substance :rolleyes: ;)