BMW E46 Fanatics Forum banner

LPG in a BMW?

  • Oh certainly, awesome! I'd fit LPG to mine!

    Votes: 26 68.4%
  • LPG better than diesel? Pffft.

    Votes: 1 2.6%
  • Shoot the man, save his BMW from LPG!

    Votes: 11 28.9%
1 - 20 of 29 Posts

·
Registered
Joined
·
1,784 Posts
Discussion Starter #1
What do you guys think? A certain friend wants to fit an LPG conversion to his 323Ci, stating that it would save him 2000Euro every 11k miles or so. Also says LPG is better then diesel:eek:

What say you, fanatics? Should I take his BMW away from him? Are there ANY benefits at all to a LPG system apart from lower running costs? LPG does burn at a higher temperature and I would think it could damage the engine.
 

·
Premium Member
Joined
·
7,648 Posts
LPG combustion produces LESS heat than petrol, although the actual flame temperature is slightly higher

Direct quote from some very knowledgeable person over in e30zone
"As for general wear on the engine, that is greatly reduced because a) LPG does not contaminate the oil like petrol does - the oil comes out of the engine a similar colour to what it went in when you change it, instead of the black gunge that results from petrol running, and b) LPG does not require enrichment for start up and cold running, so there is no washing of oil off the cylinder walls, which is when about 80% of engine wear occurs.
You must certainly not use platinum plugs! LPG doesn't like those at all. Some engines with marginal ignition systems run better on iridium plugs, but there's no problem at all with any BMW engine.
One thing you will find, is that MPG decreases by around 20%. This is simply because LPG is about 20% less dense than petrol. Weight for weight, the mileage will be about the same."
 

·
Modifiziertes ///Mitglied
Joined
·
27,022 Posts
1. It's MUCH cheaper, actually over 50% cheaper than gasoline
2. It has no side effecty on your car
3. you can put the tank into your spare tire well
4. You can switch between LPG and standard gasoline even when the car is on
5. therefor you have two tanks, double distance
6. It burns cleaner and is better for the environment
 

·
Registered
Joined
·
1,784 Posts
Discussion Starter #6
Says the Jeremy Clarkson fan and diesel driver (X5 3.0d). That's irony right there, since he says that diesel is the fuel of satan :rofl:
:evil:MUAHAHAHAHAHAHA!! :evil:​
 

·
Modifiziertes ///Mitglied
Joined
·
27,022 Posts
LPG combustion produces LESS heat than petrol, although the actual flame temperature is slightly higher

Direct quote from some very knowledgeable person over in e30zone
"As for general wear on the engine, that is greatly reduced because a) LPG does not contaminate the oil like petrol does - the oil comes out of the engine a similar colour to what it went in when you change it, instead of the black gunge that results from petrol running, and b) LPG does not require enrichment for start up and cold running, so there is no washing of oil off the cylinder walls, which is when about 80% of engine wear occurs.
You must certainly not use platinum plugs! LPG doesn't like those at all. Some engines with marginal ignition systems run better on iridium plugs, but there's no problem at all with any BMW engine.
One thing you will find, is that MPG decreases by around 20%. This is simply because LPG is about 20% less dense than petrol. Weight for weight, the mileage will be about the same."
Actually, it's more around 10% lower mileage. But since you save around 50-60% in costs, there ya go.

Also, liquid injection LPG system may have up to 3-5% in performance gains, whereas the vapor systems may have a slight performance loss (also 3-5%).
 

·
Registered
Joined
·
1,411 Posts
How long does it take to fill up and how readily available is LPG in each town/city?
I'm liking the pro side of this argument. I'd say yes.
 

·
Modifiziertes ///Mitglied
Joined
·
27,022 Posts
It's a small nozzle that can be fitted behind the tank filling cap so you can't see it. The tank gets filled with 8 bars of pressure, so it should go pretty fast.
 

·
Registered
Joined
·
133 Posts
Well actually you will pay more than you do for BBQ LPG in the US because the stuff you get for your BBQ doesn't have the on-road tax. If you have a vehicle the runs on LPG add about .60-.70 for tax from the feds and state. Plus, legally you cant just have a tank sitting in your trunk. You have to have a DOT approved tank that is impact resistant and a fuel cut of system so you don't release a cloud of highly explosive gas during a wreck.

Also, what type of fuel delivery system is your friend considering? I don't think standard pumps will function with the LPG. It gets extremely cold as it expands to a gas.

Other than that I am interested, someone should try it and report back. My forlkift's are the best running, and lowest operating cost, pieces of equipment I own. One of them has run for 65 years on the same motor (says the guy I bought it from) . May be I should just take that to and from work. :p
 

·
Modifiziertes ///Mitglied
Joined
·
27,022 Posts
Autogas has it's own tank, fuel pump, fuel lines and injection system:
http://en.wikipedia.org/wiki/Autogas

And yes, the tank is not just a standard sheet of metal-style tank, it's a special safety tank with extra thick walls tat can handle every sort of condition, including the interior pressure of the gas itself, which as said would be around 8 bars.
So basically, the tank is safer than the stock gasoline tank.
 

·
Registered
Joined
·
2,567 Posts
Running your car on LPG will be more expensive than using gas. Trust me, I've looked into it and it won't save you any money.
 

·
Registered
Joined
·
1,784 Posts
Discussion Starter #16
Fine instead of me making fun of our resident German (Ray), let's make this informative.

Someone care to share the costs of a LPG installation?
Does addidional maintenance need to be performed on the car?
Are service intervals the same or shortened?
 

·
Modifiziertes ///Mitglied
Joined
·
27,022 Posts
A LPG system with vaporized injection costs around 2000EUR (~3200USD)
The liquid injection costs around 3000EUR.

As mentioned, a liter of LPG costs 0.60EUR, a liter of gasoline costs over 1.50EUR. So if you drive 10.000km with LPG instead of gas, you save 1000EUR, calculated with the mileage of my car.

No additional maintenance, no additional service intervals.
 

·
Registered
Joined
·
2,567 Posts
Well according to my studies, the price of one U.S. gallon of LPG is somewhere around $4.10-$4.65 depending on where and how much you purchase. That being said, The BTU of 1 U.S. gallon of LPG is 90,800, whereas 1 gallon of gas contains 125,000 BTU. A difference of 37.6%. Using propane at the $4.10 price would be equivalent of paying $5.64 per gallon of gasoline. Though the octane rating of propane is higher, theoretically even if you bumped up the compression of your motor there would be no recovery on the price difference when including the current prices of propane and the cost of installation. I hope this helps clarify the "savings" and helps you to make a wise decision.
 
1 - 20 of 29 Posts
Top