Gas vs propane tractors

Been reading a lot about development of propane tractor engines back in the 50's. How is propane fuel economy vs gas. Was it just a price issue or can you get more work from a gallon of propane vs gas like you do diesels.

Propane has less btu and will do less work per gallon than gas will. Nebraska tractor tests will often have test results for the various fuel types for each tractor. I can get Nebraska Tractor test results for a Ford 801 LP, gas, or diesel. The test results allow comparison from a scientific, controlled environment vs "my neighbor said his tractor only burns XXX amount of fuel".

The main value of a propane engine in a 1957 Ford tractor, according to the local Ford tractor dealer, was longevity of the engine, or, put another way, much longer intervals between overhauls. I don't know of one propane tractor within a 30 mile radius at that time. I don't know if the dealer had even sold any. I can remember seeing one used Allis Chalmers advertised in the Wisconsin State Farmer that was propaned equipped. I was interested enough in it to place a call to a local fuel dealership that sold a lot of ag fuel. The dealer advised against buying one for various reasons and I dropped the whole idea. Never saw one operating. Gasoline back then (1957) was about .17c per gallon delivered to the farm. Shortly thereafter, in the 60s, diesels pretty much began to dominate the market until, finally, they dominated completely.

You can do this research yourself by perusing the Nebraska tractor test results.

At the price of gasoline back in the 50's it had to be for engine life. It runs much cleaner than gasoline, engines don't carbon up in the combustion chamber, and the crankcase stays cleaner, fewer oil changes.

In the 70-80's when gas was high, propane was cheaper to operate, plus the longer engine life. Took a while for the gov to get around to applying road taxes too, so it was a very popular conversion on cars and trucks!

It does not make as much power as gasoline, so consumption will be a little higher, power will be a little less. I drove some propane converted cars and trucks, I couldn't tell any power loss, they ran very well.

One of the biggest markets now is for indoor equipment, forklifts, floor sweepers, etc. Much less smell and emissions.

There are couple reasons LP was popular in west Texas. It was penny a gallon so lots of cotton farmers used it, even converting gasoline over to lp either by aftermarket or bootleg systems. Another reason was migrant workers couldnt drain gas out of tractors for their cars, of course there was a lot of drip gas used too.

Before I was in grade school HS kids were stealing gas out of the neighbor's gas tank.

Neighbor would hide in his corn crib with a double barrel shotgun.

He would let off a round to signal my Dad to call the cops.

I wonder if LP was the farmer's solution to stealing gas?

Dad also had a propane powered irrigation pump.
It could run non-stop and not run out of fuel.
The propane was very clean burning and the oil stays clean longer.

Where I grew up (Sauk County, WI), Minneapolis Moline pushed LP-gas tractors hard. Price advantage eventually got too little to compete with Diesel.

I converted a 76 Ford f250 to propane. It would get 12 to 13 MPG on gas and 10 on propane, but propane is half the price of gas. It had a 360 cubic inch engine with 8 to one compression ratio. I swapped in a 460 with 10 to one compression ratio. It got 10 MPG on both gas and propane. I think it may have had a little more power on propane. Propane like a compression ratio of 14 to one. I'm pretty sure propane might put out more power than gas at that compression ratio.
My friend was telling me about running diesels on both diesel and propane and they put out more power than just diesel or propane alone.

Worked for a propane company for over twenty years. Converted and maintained many propane tractors. All my vehicles and small engines ran on propane. Didn't buy one gallon of gasoline from 1969 until 1989 for any of my units. Cost of converting electronic controlled engines ruined it for me

My father said it was because back in the 30's propane was a by product of the refining process, with more supply than demand, so it was dirt cheap. During WW2 they developed the cracking process of refining, so they could extract what they wanted, we needed lots of avgas!

I think you are thinking of distillate, and not propane.

On our ranch trucks back in the mid '60s. The gas got 13mpg empty. The propane got 10 mpg. Pulling a 16ft cattle trailer full of cattle, the gas got 9 mpg, the propane got 5mpg. The propane truck did have an air hose on it so it was used for emergency tire inflation. (fact, not a recommendation) Had a 1000 gal propane tank at the ranch house. they recommend 3000 mile oil changes on both trucks.

We've used old Minneapolis-Moline gas and LPG tractors side by side. Learned the propane tractor uses 25 - 30% more fuel than the gasser doing the same work. Offsetting this is the LPG tractor runs much cleaner - the oil remains remarkable clean even after 150 hours. And the exhaust doesn't stink!

However in cold weather the propane tractor is more difficult to start - involves operating gas and vapor withdrawal valves in proper order and at the proper times as the engine warms up.

Finally you DON'T want to let an LPG tractor run out of fuel in the field (you can't simply dump in a couple gallons from a jerry can, fire it back up then run it back to the barn!)

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Somewhat related, the school district I occasionally drive bus for is phasing out diesel and gasoline engines in favor of liquid injected propane buses. Fuel mileage differences are significant: A gas bus will deliver 5 - 6 mpg on a 100 mile trip; the LPG only 3 - 4 mpg. (The older diesels are good for 7 - 8 mpg...)

Also the LPG buses are slower to get started - hot or cold. After turning the key there's about a 1 minute wait while the fuel system purges/pumps and the computer actually cranks the engine.

However the LPG buses have plenty of power, and the exhaust smell is much more tolerable.

I have a JI Case 930 lp tractor. Ran it today blowing snow...no anti-gel needed. Starts good at -25 on vapor and switch to liquid after the engine warms up Uses a third more fuel than the 930 diesels and not as much power although the diesels are 401 ci and the lp engine is 377ci. Back in the late 60s lp was .06$ and diesel was .15$.

Pictures from last winter...had to use the diesel on the blower while I put a water pump in the lp tractor.

Moms 1965 Delta 88 LS,425 ci ran 10 mpg on premium(ethel) we never checked mileage on LP but the power was down. THe El Camino(350) dad drove(bought from the lp dealer used) ran fine. Of course it was about half the weight of the 88. Missouri added a $60.00 dollar sticker for running LP because most people were not paying road use tax. We always paid at the dealer(mom worked in the office) $60.00 extra in the 70s was too much to make it pay and we took the conversion off.

Both!

In some places its still called Butane, witch was a earlier gas that was liquid and then vaporized. It was low pressure, 100 psi and would not vaporize at low temps.It was put in tanks buried in ground. Here in West Central Tx there are several around, not being used. Where grew up in Oklahoma our tank was in ground and last time stopped there it was still in ground