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Discussion Starter · #1 ·

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Goddamit,

If the cost of fuel and thus running expense is such an issue, then why buy an M5 in the first place???

Bet the dealers laugh their *** off.









IvanDias said:
Here we are, I'm nothing to do with this zero-rated seller.

http://cgi.ebay.co.uk/BMW-M5-3-8L-1...4575294350QQcategoryZ9837QQrdZ1QQcmdZViewItem


What's with this then?

I thought that LPG was upsuitable for high-revving engines, pretty much 6000+rpm?

I'd hate to think this might run lean, though surely they would have checked this???

Those injectors look odd on the engine!


Ivan.
 

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I'm not anything to do with the seller either but I did have a look at LPG a bit back, (not for the M5 though). Have a look at http://www.prins-lpg.com/en/products/vsi/index.html

It's look way better than the old systems that used to just bleed gas into the air intake.

Don't think I'll go for it though, all that extra pipework in the hottest part of the engine bay & a nice big tank in the boot, (or you lose your spare wheel with a 'doughnut' tank).

LPG does keep your engine internals clean though - no carbon build-up in the oil.

I'll be back with a car soon - just finishing off the house extension!

Mickle
 

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Using the latest LPG systems (sequential, computer controlled) wont affect your performance, it can even give you some extra Nm (thats what I heard)

but...
I still think its profanation to do this on a ///M5
 

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I thought only the Dutch were stupid enough to build in LPG in there cars.The fuel doesn't have good lubrication and causes extra heat.A lot of "normal" cars have problems with it,let alone special ones.Calculations tell that normal petrol is also cheaper to use(turning point at about 25000km/year)Very environment friedly though,thats why we have to pay extra tax for it in Holland......
 

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Discussion Starter · #6 ·
Cor-Jan said:
Very environment friedly though,thats why we have to pay extra tax for it in Holland......
In the UK, LPG is cheaper than petrol/diesel, as they are trying to get people to convert. Problem is that filling stations are far a few between.

Seller quotes 38p/litre for LPG, (I've no idea if this correct), but I do know that you use a lot more litres than petrol to generate the same power and drive the same distance. UK petrol currently 91p/l to 109p/l depending where you buy.

UK sources quote 25k miles to break even on the average company car assuming a conversion cost of £1500 or so.


Remember diesel prices were lower taxed, then they went up when everyone had diesel cars.

Watch out that you don't buy a LPG conversion 5 minutes before the tax goes up! LOL!!


Ivan.
 

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Hi There,

I've got a Prins LPG system fitted to my 1999 Daimler Super V8 - basically the LWB version of the V8-Engined Jaguar XJR.

There's pros and cons to having the system fitted:-

  • Engine Returns circa 21Mpg on Petrol in normal use - circa 18Mpg on LPG
  • Engine runs cleaner - needs fewer Oil Changes
  • LPG in the Watford Area is around 36-39 pence per litre - pretty cheap at circa £22.00 for a full tank
  • No noticable loss in performance - even at full tilt.
However, there are some trade-offs :-
  • The Gas Tank is in the boot under the floor - in the spare wheel well. If you're familiar with these cars, you'll know that they have quite a long rear overhang - and this means the weight bias of the car is shifted more over the back wheels - and you can feel it - particularly when the LPG Tank is full - the handling balance is not quite as neutral as it was before the system was fitted - could really do with 10-15% stiffer springs and dampers to compensate - ~I reckon.
  • If you do the suspension modifications, then that's an additional cost - so what's the point of the conversion ?!
I'm happy with the car the way it is, to be honest - it spends it's time mainly on motorways - and so the wieght issue is less pressing than would otherwise be if being chucked enthusiastically down 'A' Roads.

The thing to remember is that LPG does add quite a bit of weight to the car overall - I'd like to drive an M5 with it fitted - before I bought it.
 

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I can understand for people that do HUGE miles or very old V8's with single figure performance.


But, I think a sail and rigging would be a better option for the M5, espeically with all the torandos around Birmingham. Cue Ivan for some photoshop work.






:thumbsup:
 

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can someone explain to me what lpg is? Ive never even heard of it? Is there any other names for it?
 

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mickle said:
LPG = Liquid Petroleum Gas
CNG = Compressed Natural Gas

Regards,

Mickle
so how is Liquid Petroleum Gas different from petrol/gasoline?
 

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Discussion Starter · #12 · (Edited)
redl1nerpm said:
so how is Liquid Petroleum Gas different from petrol/gasoline?
It's only a liquid under pressure, hence the toroid (donut) shaped pressurised extra gas tank in the boot, taking up more space.

Ever been camping? You know those portable gas stoves, butane? Broadly similar, you can hear the liquid if you shake the can, but it comes out the top as a gas rather than a liquid.

LPG has extra injectors that allow the gas in to the engine where it burns instead of petrol. It comes as a gas, not a spray like gasoline/petrol, so arguably mixes better, burns cleaner.

LPG has a lower calorific value than petrol, (less "energy" store in it), so you need to burn more of it (sort of like how a lump of mahogany will burn longer and release more heat than a lump of balsa wood, so you'd need less mahogany to heat a given room size in a fireplace), to achive the same power output in a motor car.

The system is installed as well as the existing petrol system, with a switch to select fuelling method, so you can continue on petrol when you run out of LPG, which is handy, as I'd wager there are more topless garages than LPG garages in the UK!



I'm a dreadfully un-politically correct kinda guy. I like to burn petrol, loads of it, so much so that I even add an innocent fluffy kitten to every full tank! Roll on when I can have a *Hydrogen* powered car. Now there's a mans fuel! Roaring flame exhausts fifty feet long out of the... afterburners!... Oh... What?.. Only water vapour? That's rubbish then...
 

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///Mysliwiec said:
Using the latest LPG systems (sequential, computer controlled) wont affect your performance, it can even give you some extra Nm (thats what I heard)

but...
I still think its profanation to do this on a ///M5
The last time I heard of someone trying LPG in a seriously fast machine was Charles Burnett III who owned the then Class 2 world speed record powerboat. On petrol/oil ( 3 Mercury outboards, catamarran hull ) it did 140mph, on LPG it did 104. I suspect similiar would be true today on an M5 despite advances in technology.

:cheers:

ralph (vadas1)
 

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IvanDias said:
I'm a dreadfully un-politically correct kinda guy. I like to burn petrol, loads of it, so much so that I even add an innocent fluffy kitten to every full tank! Roll on when I can have a *Hydrogen* powered car. Now there's a mans fuel! Roaring flame exhausts fifty feet long out of the... afterburners!... Oh... What?.. Only water vapour? That's rubbish then...
Ivan,

That's the funniest thing I've read on this board for ages !

I went LPG on my Daimler (JAG), as I'm broadly similar to you in terms of the need for BHPs

- it came down to a a choice between chopping it in for a Diesel Golf/Passat-style motor with around 40-45MPG, or keeping a 370BHP motorised sofa (That's what it is - let's be quite clear about this !) - which based on current LPG vs unleaded prices, returns the cash equivalent of a little over 40Mpg.

However, one benefit I quite like is this - it's painted black, and most people mistake me for the local mayor/councillor when they see me apporaching in their rear-view mirror, and get out of my way !!:M5launch:

....it makes the ///M that much more enjoyable when I do drive it - proper handling and a real gearbox.
 

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vadas1 said:
The last time I heard of someone trying LPG in a seriously fast machine was Charles Burnett III who owned the then Class 2 world speed record powerboat. On petrol/oil ( 3 Mercury outboards, catamarran hull ) it did 140mph, on LPG it did 104. I suspect similiar would be true today on an M5 despite advances in technology.

:cheers:

ralph (vadas1)
Latest LPG are quite expensive (1000-2000 euro) but properly fitted shows less than 5% horsepower loss (dyno proved in many tv shows, forums etc.) and you can set it to burn more lpg so the mpg will be worse, but performance can be better than on a petrol.

AFAIK, LPG isnt used in US, and in UE its uncommon. Coming to the eastern europe you`ll see that LPG is as common as diesel and using only patrol is becoming something rare. You can even buy new car with LPG installation (VW).

As I sad before, it should be punished to do that on M5:crying:
 
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