Would this be barbarian?

flatty · 19-03-2017 9:04am #1

I have as a second car a beautiful low mileage impeccable merc 500sl. It's 1994 Japanese import, so rhd, no rust etc. It's pretty much pristine. Hood works, hard top,etc.
Now my other car is also an impractical enough two-ish seater petrol guzzler.
I've been thinking of selling the merc, as I don't often drive it, and getting a runaround like a nissan leaf.
I can afford the petrol, but it only does about 22 ish mpg, and it irks me slightly for whatever reason, probably Catholic guilt.
One other option however would be to get it lpg converted. I told a pal, who was horrified, and said that that particular engine remains one of the finest ever built, and it would be a barbaric act. He days it's appreciating in value anyway, and I'd be an idiot to molest it.
It is, however, a cool looking car imo, with a good sound system, and lovely to drive with the roof down, and it would seem that lpg might suit my needs. A friend had his disco lpg'd when.it was new, it's now done 200k miles and it's been fantastic for him. I'm also odd enough that the cost of the conversion wouldn't bother me.

Has anyone any thoughts?

colm_mcm · 19-03-2017 9:07am

How much driving are you actually doing on each car, how much will you actually save by changing to LPG, and how much will the conversion cost.

flatty · 19-03-2017 9:14am

colm_mcm wrote: »

How much driving are you actually doing on each car, how much will you actually save by changing to LPG, and how much will the conversion cost.

I'm doing about I'd say 6-8 k per year total. I think the conversion to be done properly would be about 1500 sterling. (rough estimate, I'd go to the lad that did your man's disco)
So, in that car, I'd do maybe 3k per year (it's been garaged for the winter), but I'd tend to use it more if it were on lpg.

Isambard · 19-03-2017 10:19am

if I have got it correct, the conversion entails a fitting on top of the carb and a gas tank, which can fit the spare wheel well or somewhere out of the way. you wouldn't be changing the engine at all.

Tzar Chasm · 19-03-2017 10:32am

If it means getting use out of the car instead of it wasting away in a shed then do it.

When i read the title I feared you might have been contemplating the Diesel route

stimpson · 19-03-2017 10:41am

flatty wrote: »

I'm doing about I'd say 6-8 k per year total. I think the conversion to be done properly would be about 1500 sterling. (rough estimate, I'd go to the lad that did your man's disco)
So, in that car, I'd do maybe 3k per year (it's been garaged for the winter), but I'd tend to use it more if it were on lpg.

3000 km at 22 mpg works out about €600 in fuel per year. You'll save about 40% on lpg, so a saving of around €250 per year. So 6 years to break even. And that's not including lpg servicing. Totally not worth it.

Max Headroom · 19-03-2017 11:12am

flatty wrote: »

I have as a second car a beautiful low mileage impeccable merc 500sl. It's 1994 Japanese import, so rhd, no rust etc. It's pretty much pristine. Hood works, hard top,etc.
Now my other car is also an impractical enough two-ish seater petrol guzzler.
I've been thinking of selling the merc, as I don't often drive it, and getting a runaround like a nissan leaf.
I can afford the petrol, but it only does about 22 ish mpg, and it irks me slightly for whatever reason, probably Catholic guilt.
One other option however would be to get it lpg converted. I told a pal, who was horrified, and said that that particular engine remains one of the finest ever built, and it would be a barbaric act. He days it's appreciating in value anyway, and I'd be an idiot to molest it.
It is, however, a cool looking car imo, with a good sound system, and lovely to drive with the roof down, and it would seem that lpg might suit my needs. A friend had his disco lpg'd when.it was new, it's now done 200k miles and it's been fantastic for him. I'm also odd enough that the cost of the conversion wouldn't bother me.

Has anyone any thoughts?

Your "pal" is an idiot and clearly hasnt a clue.........

Isambard wrote: »

if I have got it correct, the conversion entails a fitting on top of the carb and a gas tank, which can fit the spare wheel well or somewhere out of the way. you wouldn't be changing the engine at all.

Right....it doesnt affect the look of the car in any way....and can be removed at any stage...

PaulK_CCI · 19-03-2017 2:12pm

Tricky one, but it really depends on your long term vision with the car. If your merc is a pristine, low mileage example and in the long run you would like to hang on to it, with the vision of possibly sell it a good few years down the line and intend to keep it in a pristine shape as possible for the odd drive and weekend jaunt, than no, I would not convert the car to LPG. This would be even more so, if your car is a rare model, for example the 6.0 AMG or something...

Note these SL's will only increase in value along the years, and even though you do not alter the engine or appearance of your car, it will affect the value if it is clear that the car was converted to LPG. It means to a prospective buyer that you made the deliberate choice to start clocking up more miles in it, and even though the changes to body/interior/engine are very minimal, they make the car less pristine.

If you are not overly fussed with getting a premium return back on the car if you ever would sell it many years down the line, and are more interested in enjoying it more now, then I would say, do your maths as in how many miles and in how many years the investment is earned back, and decide wether it makes sense or not. Make sure you have the conversion done by someone who knows what they are doing, and nothing is as bad, as a badly installed LPG system. These fuel injected ECU regulated engines need a specialised engine management system to get the best out of them.

Bigus · 19-03-2017 8:13pm

stimpson wrote: »

3000 km at 22 mpg works out about €600 in fuel per year. You'll save about 40% on lpg, so a saving of around €250 per year. So 6 years to break even. And that's not including lpg servicing. Totally not worth it.

Seeing as you mention a Leaf , An electric plug in block heater on the SL would nearly save you as much money if the engine was always up to near operating temperature from cold start even in summer.

flatty · 19-03-2017 11:50pm

PaulK_CCI wrote: »

Tricky one, but it really depends on your long term vision with the car. If your merc is a pristine, low mileage example and in the long run you would like to hang on to it, with the vision of possibly sell it a good few years down the line and intend to keep it in a pristine shape as possible for the odd drive and weekend jaunt, than no, I would not convert the car to LPG. This would be even more so, if your car is a rare model, for example the 6.0 AMG or something...

Note these SL's will only increase in value along the years, and even though you do not alter the engine or appearance of your car, it will affect the value if it is clear that the car was converted to LPG. It means to a prospective buyer that you made the deliberate choice to start clocking up more miles in it, and even though the changes to body/interior/engine are very minimal, they make the car less pristine.

If you are not overly fussed with getting a premium return back on the car if you ever would sell it many years down the line, and are more interested in enjoying it more now, then I would say, do your maths as in how many miles and in how many years the investment is earned back, and decide wether it makes sense or not. Make sure you have the conversion done by someone who knows what they are doing, and nothing is as bad, as a badly installed LPG system. These fuel injected ECU regulated engines need a specialised engine management system to get the best out of them.

I was led to believe that an lpg conversion fundamentally altered the engine, and could never be reversed.???

PaulK_CCI · 20-03-2017 2:22am

No, it doesn't. It's quite easily reversed and you're only left with a couple of small holes for fuel lines from the tank in the boot and some remants for filler holes etc. If you clocked up a serious amount of miles, you will have caused more wear and tear to your head(s) and valves, because LPG autogas burns hotter than petrol and in the long run causes more wear, but we are talking 100k+ miles.
Here in the Netherlands, LPG autogas is/was fitted on a lot of classics, mostly Yanks and big engined car, like the Mercs and BMW's. However, a couple of years back the government decided to put a halt to the people specifically buying Merc 190 diesels and Audi diesels, and to the people buying classics and sticking LPG gas conversions in them, purely to use as their daily driver. At the time, there was no annual road tax, and since Diesel and LPG carry less "loading", it would be very cheap motoring for these drivers. So suddenly 30 - 40 year old Diesel and LPG converted cars could no longer avail of the cheap road tax any longer and were classed with the normal (double) tax rate! The Diesel owners were basically scr*wed, but the LPG owners could just take out the LPG system and return to petrol. So returning to petrol is always possible.

spyderski · 20-03-2017 11:44am

So the car will be nearly €2,000 to tax, not to mention other running costs, and you're worried about fuel consumption over a 3,000km average annual usage? If you could magically make the engine halve its fuel consumption to 40mpg you'd be saving a whopping €300 per year.

I'd say sell it & buy the Leaf.

goochy · 24-03-2017 7:04pm

remember LPG is really only suited to long runs and not stop/ start- city driving

stimpson · 24-03-2017 7:12pm

goochy wrote: »

remember LPG is really only suited to long runs and not stop/ start- city driving

Source?

w124man · 25-03-2017 11:17pm

spyderski wrote: »

So the car will be nearly €2,000 to tax, not to mention other running costs, and you're worried about fuel consumption over a 3,000km average annual usage? If you could magically make the engine halve its fuel consumption to 40mpg you'd be saving a whopping €300 per year.

I'd say sell it & buy the Leaf.

Totally agree!

LPGing a car like this for the reasons given is totally daft. It makes no economical sense at all, none. In fact the idea is preposterous. Is it a piss take?

Type 17 · 26-03-2017 3:18pm

If you were going to put a lot of km's on the car (20-30k per year), then an LPG conversion would make sense, as you'd save a lot of money, and the originality of the car wouldn't matter as the km's/depreciation would be the main factor in its (de)valuation (your mate's Disco is a perfect example).

However, (even gently) altering a relatively rare, low-mileage car in mint condition whilst (correctly) keeping the mileage low (but therefore barely saving any money) makes little or no sense.

I have a '76 Merc with a 3.5 V8, which does 16.5 MPG, but the mileage is also low (41k at present), so I only take it out for car shows and club runs - not converting to LPG means I'm not tempted to drive it too much, which keeps the mileage down, and makes using it more special.

Tommyboy40 · 29-03-2017 5:53pm

Your problem with an SL is where to put the tank as the spare wheel well is occupied by the hydraulic pump for the top and roll bar and the petrol tank is behind the rear seats. Your poor mileage is due to the fact that earlier cars only had a 4 speed auto. Keep it original and enjoy it. Bear in mind if you only use it occasionally that they don't like being jump started and tend to kill the top control module. I have a spare hard top if you're interested

Would this be barbarian?

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