LPG Conversions

Has anyone had their car converted to LPG?

I've had a quote which would be for around 2000ukp to have the conversion done (Dual Fuel), presumably this would mean a tank in the boot which would be a bit inconvenient but the saving for me (even doing just 8000 miles a year) would then be about 500quid/year. After 4 years that's my money back and starting to save...

Except it's totally incompatible with a sports car to put a huge tank in the boot, that reduces acceleration impares cornering, disrupts the 50:50 weight distribution and lowers the engines power output, not forgetting taking the boot space.

I'm a big fan of LPG and run a 6 ltr B8 Jeep on the stuff where the fuel economy is useful and most importantly it will run on its side that carbs won't. Weigh, balance, power are also trivial in the bigger picture.

That said I've heard of some in Holland converted, but they are into all that stuff

Don't do it ...

You can never take your car to the continent again as they are barred from using the Channel Tunnel.

Being from The Netherlands (not Holland as that is a province on the left ), I have had an LPG car in the past over there. You need to realise the following:

- The engine runs hotter with associated issues.
- You will go through water hoses like nobodies business, I had several leaks over the years. No doubt they will be better now though.
- Fuel consumption is about 15 - 20% worse then with petrol, so do your saving calculations right.
- The exhaust smell is awfull (sweet smell - yuck) ...

Siftah said:

Has anyone had their car converted to LPG?

I've had a quote which would be for around 2000ukp to have the conversion done (Dual Fuel), presumably this would mean a tank in the boot which would be a bit inconvenient but the saving for me (even doing just 8000 miles a year) would then be about 500quid/year. After 4 years that's my money back and starting to save...

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Siftah you've got HUGE testicles I'll give you that...if you do it for god's sake don't tell anyone will you :rofl:

please no, not a Z4, i've done it in the past on a ford galaxy and it paid for itself within 12 months, but not a Zed, please please no

I actually thought about this as i drove to the office this morning...it was something about the 115.9 for unleaded versus 57.5 for LPG on a ptrol station on the drive...

speedski said:

I actually thought about this as i drove to the office this morning...it was something about the 115.9 for unleaded versus 57.5 for LPG on a ptrol station on the drive...

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At the moment...

Don't forget that the gap between LPG and petrol was 75%, now it's 50%, and it will be 25% soon (that's where it becomes uneconomical).

As more people swap to LPG the government loses revenue from taxes/duties on petrol/diesel and therefore has to recover it by raising those taxes/duties on LPG.

It was sold as a 'green' solution (as was diesel), but now that's been disproven there's no reason for the huge tax concessions on it.

The other reason I'd never use it is the fact that you're 3.0 will lose so much power that you might as well sell it, pocket the difference and run a 2.5 instead.

what next... the M's, Porsche, Ferrari...? Come on it's a sports car not a 7 seater!!!

peddy said:

what next... the M's, Porsche, Ferrari...? Come on it's a sports car not a 7 seater!!!

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Don't laugh, but I've seen more than one M5 with an LPG conversion, but they were mainly for continental driving tours so they didn't have to stop every 200 miles to refuel.

It's strange that my e34 M5 OBC 'reported' a fuel economy of 22mpg average over it's 6 years, yet would not get more than 300 miles out of a 90 litre tank

PS, don't ever run out of petrol on the approach to Heathrow Airport as you'll see an armed patrol very shortly (although the driver was cute - and female).

mmm-five said:

Don't laugh

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too late.... :rofl: :rofl: :rofl: :rofl:

I say if you're worried about the petrol costs of a particular sports car then there's no point in buying it in the first place!

Best to go on the bus and save the zed for pleasure running petrol!

Stick with petrol. And just work out how much extra you pay when the fuel prices increase. A 5p hike on a 40 litre top up is only two quid...hardly worth getting excited about now is it. We all happily pay much more for a pint of beer

No...... don't do it!

Or as some seem to have done on here, buy a cheap run-around, small engined, high MPG car for work/running about, and save the Zed for pleasurable driving!

Gents,

I looked on this forum when I was considering an lpg conversion for my second z4. There seemed to be a lot of opinion (some of it helpful) but not a lot of personal experience so I thought I would add my experience of buying a z4 and running it on lpg for 18,000 miles over the last year.

I bought an 08 2.5i SE with 6,000 miles earlier this year. It runs beautifully smoothly but clearly is not as fast as either si version. (I had a 2.5si before).

Before getting into the opinion side can I set the record straight on a few basic issues that seem to be batting back and forth.

There is no noticable difference in power driving the car.
LPG has an octane rating of 107, which is why the engine runs smoother than on petrol (Noticably so in fact)
LPG is more environmentally, engine and people friendly as the particulates it produces are much less complex (and toxic) than burning petrol which has many impurities within it. Propane is a very simple organic chemical that burns very cleanly.
LPG has 20% less energy than petrol per litre and this is why you will get less mpg from lpg (20% less in fact).
The tank does take up half your boot space. Well mine does anyway, but it is 50 litres nominal (you can only fill it to 80% for safety) and it does 220-240 miles for about £25-£30 depending where you fill up.
The Z4 (2006- 2009) is, I think, one of the last BMW models to use the valvetronic non direct injection engine (in Europe) and it is very suitable for conversion to LPG as it also has hardened valves. Direct Injection has unique challenges and solutions are engine specific.
I have a PRINS conversion that cost about £1,800 with posh injectors. It will pay for itself in about a year.
I have just come back from touring Europe for two weeks (Ferry companies don't mind LPG anymore). LPG prices in Europe vary widely from 90cents on the motorway in France to 38cents to a small station in Brussels (Belgium). Typically 70p equvalent is a good average.
The tank does not in any way noticably slow the car down or affect the handling. I beat several superbikes up a tight alpine pass last week.
The annual service for the LPG is cheap and the rest of the servicing is completely as standard.
It starts on petrol for about the first mile. It runs on petrol if you manually set it to or have run out of lpg. It is automatic and is so smooth you wont notice the transition.

Downsides - Boot space is halved. You need a smart phone / sat nav to locate the LPG filling stations. More coming on line all the time though especially Shell and BP.

Would I recommend the installer I used - no. I had to tidy up the wiring afterwards. The tank and pipework was perfect though. Choose carefully.

Now on to my opinion.

Would I do this again - absolutely - it has saved me a fortune and means I can run a petrol straight 6 auto convertible for the same as my colleague runs his 4 pot manual diesel. In no way do I regularly remind him of this.

Any other questions please feel free to ask.

Excellent first post! Welcome to the forum!

when i had my ford galaxy LPG i found the main issue was the size of the tank, because it was not very big i had to fill up every 2 days, obviously this depends on the distances you travel

other main issue was smaller boot size and filling up takes a lot longer

on a sports car i would never do it, but on a bigger 4x4 or people carrier then defo

tannera - good post and some interesting stuff in it.

Can I clarify how you have 'saved a fortune'

Based upon your numbers of an £1,800 conversion and LPG at your average of 70p. I we say petrol is £1.40 then the saving is around 70p per litre. Turn that to gallons is £3.17 per gallon. If we go on 30mpg then the cost of the conversion equates to 567 gallons and 17,000 miles. Add back the 20% loss in MPG from LPG and gets me give or take at 20,000 miles to break even.

Frankly that represents 3 or 4 years motoring for most people in a Zed, so unless you have put that sort of mileage on then you are still well out of pocket. I don't doubt if the combination of high mileage and long ownership you will break even.

As I've posted before I'm in no way against LPG on the right application, but for me the numbers don't stack up unless you're a high mileage user or a really low mpg car.

Great thread I looked into this about a year ago but didn't like the idea of loosing half of what is a small boot anyway. Also the government will keep putting up the cost for LPG and it will take longer and longer to just cover the conversion costs.

Like someone else said in the end I got myself a cheap runaround for travel to work. An old X reg Puma for £2,500 FFSH and only 27K on the clock, 10 moths later and I have only had small repair bills with the Puma it does about 34-36mpg compared to 26-29mpg with the Z4 and it has saved me putting 7,000 miles on the Z (probably 8-9,000 in a full year). For me this is working out as a better option (provided your ego can handle driving an old runaround to work). It also means I don't have to drive the Z in the snow which is another big bonus and all the miles I do in my Z are pleasurable/fun miles

cj10jeeper said:

tannera - good post and some interesting stuff in it.

Can I clarify how you have 'saved a fortune'

Based upon your numbers of an £1,800 conversion and LPG at your average of 70p. I we say petrol is £1.40 then the saving is around 70p per litre. Turn that to gallons is £3.17 per gallon. If we go on 30mpg then the cost of the conversion equates to 567 gallons and 17,000 miles. Add back the 20% loss in MPG from LPG and gets me give or take at 20,000 miles to break even.

Frankly that represents 3 or 4 years motoring for most people in a Zed, so unless you have put that sort of mileage on then you are still well out of pocket. I don't doubt if the combination of high mileage and long ownership you will break even.

As I've posted before I'm in no way against LPG on the right application, but for me the numbers don't stack up unless you're a high mileage user or a really low mpg car.

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It can be tricky to work out the sums, when I looked at this as an option I didn't see the conversion cost as totally lost money as a converted car will usually be worth more. However conversions registered with TFL for the free London congestion charge after 24th Dec 2010 will not qualify so that will change future values.