LPG in classic cars - good or bad.
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Discussion

Pistom

Original Poster:

6,408 posts

188 months

Tuesday 9th July 2013
quotequote all
Ive heard a lot of talk about LPG in classics.

Running our old cars is getting more expensive as fuel goes up. LPG is still cheap. I'm not talking about putting it in a GT40 or a E type but what's the consensus of putting in in say a Rover P6 or a Mk 3 Cortina?

Would it add value or devalue it? Systems can be fitted for under £1000 and if these cars are used on touring holidays and such, the payback could be quick.

You'd lose your spare wheel but hardly any moderns have those and it's no big hardship.

Would you buy say a Zephyr that runs on gas?

Hooli

32,278 posts

229 months

Tuesday 9th July 2013
quotequote all
Depends how it was done. If it could be removed without too much damage to the car I'd consider it, but I wouldn't want to ruin a classic with all the gubbins.

As it stands I'm sort of considering it for my XJ40. It's not a classic yet (1993 is still new to me) but it might be if I keep it long enough, maybe I could claim it's a period mod?

v8250

2,747 posts

240 months

Tuesday 9th July 2013
quotequote all
I'm all for LPG as a fuel source in low mpg classics. Of course, there are some cars where a conversion would seriously detract and directly affect market value; anyone for an LPG'd DB5?? On others I could see the conversion, being able to run on dual fuel, as a distinct advantage...no doubt these words will raise eyebrows in some quarters.

As some of you may have read, I'm converting an MGB Roadster, dropping in a 4.0ltr TVR V8 and lots of other interesting bits to make the old girl a real flyer. Within the project I have priced and scoped for the possibility of having a toroidal tank installed + all the other bits. This can be done for £1200 all-in with the correct components including a valve lubrication unit. This will double the effective mpg and on long distance continental trips pay back very quickly. All with very little performance reduction.

Whilst there are some who view LPG as the 'devil's fuel', I see a conversion as a bit of fun with logically practical advantages. Only drawback is loss of usable boot space...so good job I'm a light traveller.

Pistom

Original Poster:

6,408 posts

188 months

Wednesday 10th July 2013
quotequote all
So it's OK for old practical tourer like an updated MGB or say 635CSI but no in say a DB5 or Dino. That makes sense.

Gruber

6,313 posts

243 months

Wednesday 10th July 2013
quotequote all
Personally, purely from my perspective, I don't see the point. I've tended to do no more that 3-4k miles per year in my classic BMWs over the years, and a lot of that has been trips to France by tunnel (coz I hate ferries), which would be scuppered by LPG. Plus the loss of boot space thwarts their use as a holiday car.

But back to mileage... 4,000 miles at 20 mpg = 200 gallons. Circa £6 a gallon = £1,200 in fuel.

If gas works out about half the price per litre (and I suspect its actually more than that once you take into account reduced mpg), you're saving £600 a year max.

So it takes getting on for three years to make back the installation cost, and that assumes no complications, additional servicing issues, reliability problems, fuel availability, etc etc. And I suspect "the market" values lpg'd classics lower than standard cars, so you're also decreasing the value of the vehicle.

If you're using a classic to do higher mileages, I can see the arguments in favour. But for me the downside far outweighs the upside.

Huntsman

9,313 posts

279 months

Wednesday 10th July 2013
quotequote all
Pistom said:
Ive heard a lot of talk about LPG in classics.

Running our old cars is getting more expensive as fuel goes up. LPG is still cheap. I'm not talking about putting it in a GT40 or a E type but what's the consensus of putting in in say a Rover P6 or a Mk 3 Cortina?

Would it add value or devalue it? Systems can be fitted for under £1000 and if these cars are used on touring holidays and such, the payback could be quick.

You'd lose your spare wheel but hardly any moderns have those and it's no big hardship.

Would you buy say a Zephyr that runs on gas?
Funny you should post this, I wondered last night about running a P6 V8 on LPG as a daily driver.

spoodler

2,304 posts

184 months

Wednesday 10th July 2013
quotequote all
Gruber said:
Personally, purely from my perspective, I don't see the point. I've tended to do no more that 3-4k miles per year in my classic BMWs over the years, and a lot of that has been trips to France by tunnel (coz I hate ferries), which would be scuppered by LPG. Plus the loss of boot space thwarts their use as a holiday car.

But back to mileage... 4,000 miles at 20 mpg = 200 gallons. Circa £6 a gallon = £1,200 in fuel.

If gas works out about half the price per litre (and I suspect its actually more than that once you take into account reduced mpg), you're saving £600 a year max.

So it takes getting on for three years to make back the installation cost, and that assumes no complications, additional servicing issues, reliability problems, fuel availability, etc etc. And I suspect "the market" values lpg'd classics lower than standard cars, so you're also decreasing the value of the vehicle.

If you're using a classic to do higher mileages, I can see the arguments in favour. But for me the downside far outweighs the upside.
Pretty much agree with all this.
Don't forget that any saving is down to the difference in fuel costs (not due to efficiency or greater miles per gallon) and that on l.p.g. fuel consumption is generally higher and power output lower than the equivalent vehicle on petrol.
Also, don't forget that if l.p.g. use increases the chances of the government raising the tax level on it is fairly high - remember when diesel was half the price of petrol?

Pistom

Original Poster:

6,408 posts

188 months

Wednesday 10th July 2013
quotequote all
Having used a modern LPG car, it's really nice filling up for £30 and driving so far on so little.

I like using classics and I was wondering how others felt.

Gruber

6,313 posts

243 months

Wednesday 10th July 2013
quotequote all
Pistom said:
Having used a modern LPG car, it's really nice filling up for £30 and driving so far on so little.

I like using classics and I was wondering how others felt.
I can understand that. My daily commuter is a little 125cc Honda put-put. The tank holds about 6 litres of petrol and it needs filling no more than every three weeks at circa 95mpg and £8.00 a go.

mikey77

707 posts

217 months

Wednesday 10th July 2013
quotequote all
Bad.

tog

4,948 posts

257 months

Wednesday 10th July 2013
quotequote all
Huntsman said:
Funny you should post this, I wondered last night about running a P6 V8 on LPG as a daily driver.
You'd use up a lot of the not-ample boot space, unless you go for a boot-mount spare.

plasticpig

12,932 posts

254 months

Wednesday 10th July 2013
quotequote all
Gruber said:
Personally, purely from my perspective, I don't see the point. I've tended to do no more that 3-4k miles per year in my classic BMWs over the years, and a lot of that has been trips to France by tunnel (coz I hate ferries), which would be scuppered by LPG. Plus the loss of boot space thwarts their use as a holiday car.
Losing boot space means you have a cheap conversion. Doing it properly is ripping out the old fuel tank and fitting an LPG tank under the body with a smaller fuel tank. A 20 liter tank is fine for an LPG conversion. Best conversion I have ever seen is on an XJ6 SIII where they had removed both tanks and replaced them with LPG tanks. On one side you lifted the fuel cap to find a valve for the LPG tanks and the other side was to fill the small replacement petrol tank. It was a very neat job
and you still had the same boot space.



Edited by plasticpig on Wednesday 10th July 20:16

Pistom

Original Poster:

6,408 posts

188 months

Wednesday 10th July 2013
quotequote all
mikey77 said:
Bad.
Why

nta16

7,898 posts

263 months

Wednesday 10th July 2013
quotequote all
first thing I can tell you one place that does LPG conversions to avoid like the plague but obviously (unfortunately) not on here so you'd have to PM me if you want/need to know

as said for the economics you'd not bother if you're only going to do low mileage and are worried about values when you sell the car

IIRC someone who runs LPG said how much cleaner there engine oil was at changes

as for losing the spare wheel I've not used a spare wheel in my daily used classics for 20+ years without problems, I just carry a manual footpump

one thing to note, unless things have changed some petrol stations that sell LPG (used to be / are?) out of stock for long periods or lots of occasions

Pistom

Original Poster:

6,408 posts

188 months

Wednesday 10th July 2013
quotequote all
A P6 would be such a practical mile muncher if it was cheaper to fuel. I really don't see why LPG would adversely affect its value as there must be buyers who would value the low running costs over originality.

I'd drive my car every day if it was cheaper to fuel.

Gruber

6,313 posts

243 months

Wednesday 10th July 2013
quotequote all
Pistom said:
A P6 would be such a practical mile muncher if it was cheaper to fuel. I really don't see why LPG would adversely affect its value as there must be buyers who would value the low running costs over originality.

I'd drive my car every day if it was cheaper to fuel.
Supply and demand.

There will be fewer classic car buyers out there wanting LPG. Most - especially those looking to spend good money on a Condition 1 car - will want a standard, original, un-messed-with example.

Most classic buyers don't want an every day car - they want something special to love and cherish and insure on the cheap. Having LPG will be an attraction for a relatively small number of an already limited pool.

Huntsman

9,313 posts

279 months

Wednesday 10th July 2013
quotequote all
tog said:
You'd use up a lot of the not-ample boot space, unless you go for a boot-mount spare.
P6 boot is huge? Well I thought it was on the 2 I had. But I take your point, the tanks do get right in the way.

nta16

7,898 posts

263 months

Thursday 11th July 2013
quotequote all
Gruber said:
Most classic buyers don't want an every day car - they want something special to love and cherish and insure on the cheap.
. . . and very rarely drive


Gruber said:
Having LPG will be an attraction for a relatively small number of an already limited pool.
this is true

roscobbc

4,040 posts

271 months

Thursday 11th July 2013
quotequote all
Seem to recall people saying that LPG being a 'dry' fuel should only be used in engines that were suitable for unleaded petrol. Are there still restrictions on taking LPG powered vehicles on Channel Ferries and Eurotunnel?

mikey77

707 posts

217 months

Thursday 11th July 2013
quotequote all
Pistom said:
mikey77 said:
Bad.
Why
Because it wasn't original then and it rarely is now. If you need a cut-price way into an old motor then maybe it would be better just to buy the picture-porn 'classic' magazines and forget owning the real thing.