Propane Gas? - PeachParts Mercedes-Benz Forum

euronatura · #1 04-23-2008, 02:39 PM

Question. Does using propane gas in a gasoline car cause any short or long term damage?
Here the galon of propane is about 1/2 the cost of gasoline. The propane importer offers and does modifications to cars to run on propane and/or gasoline.

aklim · #2 04-23-2008, 02:49 PM

I see taxis doing it all day long in Madison, WI. However, what will you do when you are out of town? Easier to find a gas station than a propane filling station.

euronatura · #3 04-23-2008, 02:51 PM

The car is rigged that it can run on either/or. It is my understanding that at start up, you start up with gasoline and then switch over to the propane tank for fuel. Therefore, it is not limiting one in distance or out of town situations.

KarTek · #4 04-23-2008, 02:52 PM

Propane works fine with no ill effects as far as reliability. I think it does, however, have less energy than gasoline.

kerry · #5 04-23-2008, 03:14 PM

It's my understanding that propane being a much cleaner fuel than gasoline, it gives the engine a longer life.

It just occurred to me that propane fueled cars are the definitive falsification of the view that propane is too flammable a gas to be used as a refrigerant in automotive air conditioners.

Matt L · #6 04-23-2008, 03:36 PM

Quote:

Originally Posted by kerry

It's my understanding that propane being a much cleaner fuel than gasoline, it gives the engine a longer life.

It just occurred to me that propane fueled cars are the definitive falsification of the view that propane is too flammable a gas to be used as a refrigerant in automotive air conditioners.

I believe that propane in your MACS unit is more dangerous than propane for the engine for two reasons.

The first is that the evaporator is inside the interior of the car and can cause an explosive mixture in the event of a leak. Especially if the car is sitting with the interior fan off, allowing the leaked propane to fall to the floor rather than be pushed out of the interior.

The second is the location of the condenser, and its likelihood of being compromised in an accident.

The second is more important to me. Since propane refrigerant is not standard for MACS here, using it may lead to liabilities if you are in an accident. It would be perfectly legal for me to use hydrocarbons in my factory-R134a system, but I'm going to decline. Other countries do use hydrocarbons, and as soon as it is generally accepted here, I will probably switch to it.

BobK · #7 04-23-2008, 03:40 PM

BTU content:
Gasoline-124,000
Propane-91,600

I have seen gas engine RVs set up for dual use since they usually carry propane anyway. Rv that could not get up a hill on gas, REALLY could not get up the hill on propane.

SwampYankee · #8 04-23-2008, 03:43 PM

Quote:

Originally Posted by euronatura

Question. Does using propane gas in a gasoline car cause any short or long term damage?
Here the galon of propane is about 1/2 the cost of gasoline. The propane importer offers and does modifications to cars to run on propane and/or gasoline.

I believe there is a BTU difference and propane is less than gasoline. Our old outdoor forklift could be run on either propane or gas although we only ran it on propane.

I've often wondered about the cost per mile aspect of propane conversion vs. gas.

Matt L · #9 04-23-2008, 04:21 PM

You can extend your oil changes with propane, so that needs to figure into the calculations.

I remember reading about a rebate in AZ for converting a vehicle to run on dual fuel, propane or gasoline. The story was that people were converting SUVs by adding a 1-lb propane container and the associated stuff to run on it, and getting thousands of dollars from AZ in the process. Just how far is 1-lb of propane going to take you?

euronatura · #10 04-23-2008, 04:25 PM

All good comments. Did not check the BTU, what I did find and the company here confirmed was that propane was about 98% efficient to gasoline. So I thought that it was pretty good. Will check more into the BTU though.

As for 1 lb. of propane, from what I have understood it is almost 5lbs of propane to make 1 galon. So from there you can roughly work the numbers.

Matt L · #11 04-23-2008, 04:27 PM

I'm guessing that 1-lb of propane could take an average full-size SUV at least two miles. Perhaps even three.

euronatura · #12 04-23-2008, 04:32 PM

Oh, as for the cost of the conversion here. I am getting a quote later but from what I was told on the phone I am looking at about US$600 for my car, the Suzuki.

Currently gas here is now about US$4.16 per galon, which makes the propane about US$2.20 per galon. My car holds about 15 galons, therefore for each fil up I am saving about US$30.00. Given the investment, I am looking at 20 tank fulls to recoup. I usually fill up about every 8 days about 5 months to recoup. But that is at current prices of gasoline and propane, if the trend continues and what the word is coming from the government here is that gasoline is going to hit US$5.37 a galon in the very near future. If this where to be the case, then I would recoup the investment in about 15 tank fulls, about 4 months. Currently my car gets on average 39km/gal or 24m/gal..........

aklim · #13 04-23-2008, 04:46 PM

We still don't know what the propane mileage will be.

BobK · #14 04-23-2008, 04:49 PM

judging by the btu per gallon, probably 25% less

aklim · #15 04-23-2008, 05:08 PM

Quote:

Originally Posted by BobK

judging by the btu per gallon, probably 25% less

Here is my calculation. I would say it is about 40% less because of the BTU and the fact that the engine wasn't designed to run it so it isn't optimized or it would be 25%. So, if propane costs $2.20 a gal, it isn't worth it. The break even point would be 0.6*4.16 and that gives us $2.50. Too close to what he is paying for it. Now if it were a taxi, it might be different but for a regular car, I don't see it.