Propane Car

Discussion in 'Homesteading Questions' started by Kirk, Feb 26, 2004.

  1. Kirk

    Kirk Well-Known Member

    Oct 30, 2003
    I wonder if anyone here has converted a car to run on propane? I have been doing some reading on it and it seems to be pretty do-able. I will soon be getting a free Ford Festiva which needs a timing belt and front seal. So I have been thinking it would be cool to have it propae powered. Any thoughts?
  2. heelpin

    heelpin Well-Known Member

    Nov 18, 2003
    Kirk, I had a 3/4 ton Ford truck with 460 engine that would run on propane or gasoline. I like the way it started in cold weather with propane and the engine would probably last a lot longer with propane but it was costly and you have less acceleration and power with propane. I only got about 5 MPG with propane and about 12 MPG with regular gasoline, you also have to have a state permit in my state to run propane. The other thing I didn't like was the space the tank took up in the truck bed and leaves continually collecting behind it causing a rust problem. To be honest I don't think its worth it.


  3. My uncle used to run a 1967 impala on both propane and gasoline. You just threw a toggle switch on the dash to go from gas to propane and back. Car ran fine on propane but you need to take up valuable trunk space with the propane cylinder. Propane also contains less energy than gasoline. I think a given volume or weight of propane contains only about 65% of the energy of the identical volume/weight of gasoline. It translates into less miles per gallon/pound. The other big problem is that if you are using propane as a fuel source for an on road vehicle you are supposed to pay fuel road tax on the fuel. I think in most states it is about 40cents per gallon. Add the tax to the propane and it is much more expensive fuel source compared to gasoline. As the other poster indicated “just not worth it. If you need an engine to last a long time go for a diesel.
  4. Well, since its a free car, I say go for it.

    But it would be nice to have a multi-fuel car. Keep it so it can run gas and propane. Another poster mentioned a toggle switch, so it would be easy to switch between the two.
  5. Janon

    Janon 993cc Geo Metro

    Aug 25, 2002
    Southern Ontario CANADA
    Here, I believe that you are exempt from sales tax when purchasing a propane powered vehicle. At one time, there were also $500 incentive programs towards the cost of the conversion. Propane has never become that popular.

    I also see natural gas powered vehicles from time to time... mostly owned by the natural gas company... little stickers in the rear window or on the rear doors of the service vehicles: "this vehicle runs on natural gas".

    Most of the natural gas or propane powered vehicles I've seen are trucks or mini-vans... no doubt because of the size of the tank(s) they must carry. Since most are "dual fuel": gasoline and the gas... you cannot get rid of your gasoline tank.

  6. Windy in KS

    Windy in KS Guest

    ARGHHHHHH!!!!!!!!! Couldn't stay logged in to post. This is better?

    I have driven LPG vehicles 10s of 1,000s of miles. I have converted several I've owned, and converted several for an LPG dealer I was working for at the time. Some have been switchable dual fuel, others straight LPG.

    At one time the taxes on LPG were less per gallon than on gasoline. That was a pretty good incentive right there to drive on the cheaper fuel. Everyone is correct in saying that LPG has less BTUs in it.

    I did overhaul a 350 cu. inch Chevy engine to set it up more properly for the use of LPG.
    I upped the compression ratio and installed a longer duration camshaft.

    After the overhaul the pickup had better power and got greater fuel mileage per gallon on LPG than it did on gasoline. Ten for LPG, eight for gasoline. I used Century brand carburetion whenever I could. The boss preferred IMPCO as he could get it at cost. I don't know if either is still sold or manufactured.

    I have never converted an auto, only trucks and pickups.

    Some states still have incentives for LPG vehicles, but only if they are purchased new. Others may have incentives for conversions, but I am not aware of them.

    If you proceed with the conversion, remember to size your tank for LPG capacity, not water gallon capacity. A tank cannot be filled 100% full because of safety factors.

    I'll try briefly to give some general conversion info for duel fuel.

    An LPG carburetor is bolted down in place of the air cleaner, via the former air cleaner bolt.

    The gasoline fuel line in cut and a solenoid activated cut off switch is installed.

    An LPG regulator/vaporizer is mounted as close to the LPG carburetor as it can be. A vapor carrying hose runs from it to the LPG carburator.

    The LPG regulator has an incoming fuel solenoid cut off similar to, but different than the gasoline cut off one. Prior to this is a fuel filter, then the line leads back to the LPG tank for connection.

    The LPG regulator cools rapidly as LPG fuel is brought through it, so it need a means of keeping it warmed enough to vaporize the fuel. The vehicle cab heater water lines are cut and tees are inserted. From one of the tees a water line goes to the regulator bringing hot water to it. A return water line goes to the other tee. (Sometimes the tees are omitted and just one line is cut rather than both. This forces all heater fluid through the regulator and would somewhat restrict flow to the heater.

    On most set ups a "Boden wire" leads from the LPG carburator to the dash of the vehicle. When a fuel switching occurrs the Boden wire is either pushed or pulled, and a plate inside of the LPG carburator is lifted or dropped depending upon which fuel you are going to and from.

    The fuel solenoids are activated from a single post double throw (SPDT) switch on the dash. When switching fuels, you move the switch to the off position and let the remainder of the fuel burn out before switching to the other fuel.

    This is probably more than you sought, but hope it helps in some manner.

    Oh, there are a variety of tank configerations for vehicles. As an example, there are tanks that fit under the side rails of a pickup just above the fenders. This allows most conventional hauling instead of taking up bed space.
  7. snoozy

    snoozy Well-Known Member Supporter

    May 10, 2002
    Kitsap Co, WA
    For several years, I had a Datsun pickup which Boeing had converted to propane for use in their hangars. It drove just fine and had the cleanest looking oil you ever saw -- never did turn black like in a regular engine. I got about 22 mpg, if I recall correctly, and I liked knowing I was contributing less noxious emissions as I drove.

    There were only 2 problems with a propane vehicle -- you had to be very aware of where you could get propane, since most gas stations don't have it, and because the gas gauge was disconnected, you had to be very aware of your mileage, because, when you run out of propane, you have to get TOWED to the propane pump. Caused some stress sometimes, when I got low and didn't know exactly how low I was, or if I'd make it to a pump. Still, I used to drive from Seattle to Vancouver and back all the time. Now in Canada, they do have propane available all over the place.