Fuel consumption guesstimate

[4570Man]

Fuel consumption is a pretty meaningless comparison to valve. My 100 hp backhoe burned a lot more fuel than my 32 hp backhoe. But the 310 would dig circles around the smaller machine and at the end of the day was the better value. A 100 hp tractor pulling a 15’ batwing mower is going to do a lot more work while burning more fuel than a smaller one.

 

[buickanddeere]

Ahh....finally a meaningful answer to an otherwise meaningless question ("Sorry OP") and meaningless answers ("Sorry everybody else").
....(IMHO) unless your comparing 2 tractors doing identical tasks the numbers don't mean much.

...but why is that Buickanddeere? Are these identical vehicles too and not just a bigger mass vehicle being moved around, up and down hills, stop/started, accelerated? Torque curve (but why)? More cylinders and a minimum fuel rate? Larger spinning mass? More energy spent moving/compressing more air...?
Why, why, why?

Have to get one’s head around the definition of the Carnot Combustion Cycle .
Increasing the compression ratio decreases efficiency BUT increasing the expansion ratio increases efficiency.
Being a heat engine . Anytime fuel is burned that does not turn the output shaft , that input energy is wasted . A partly loaded diesel or gas turbine draws in a full charge of inlet air but only uses a portion . The rest of the unused air just soaks up heat and carries that energy unused up the stack .
How is that for a semester or two of school in a few paragraphs?

 

[RalphVa]

When you guys are running your tractors what are you averaging for fuel consumption? I'm ran the tractor until the light came on and filled it. I'm not sure how many gallons it took but that was about 14 hours of operating on that tank. I have been running right around 1500-1800 RPM. I have been increasing the RPM up to 2000 now seeing that most everyone suggested that in the backhoe thread.

So what are you guys seeing on fuel consumption and please list the HP of your tractor? Usually speaking higher HP means higher fuel consumption.

35hp ~6.5 gallons/14hrs.

My longest # hours was on the JD 4010 (18.5 hp). It's overall usage was 0.45 gph. The 1025R showed 0.61 vs. 0.56 prorated off the 4010. The 2025R is showing 0.63 vs. 0.61 prorated off the 4010.

The real gem on fuel consumption is the 12.5 kw Isuzu, which is running 0.35 vs. about 0.41 prorated from the 4010. So, it's the best of the 4. I even think the 0.35 is a bit high, as it is bloated because I may have overfilled it (literally to almost the overflow from the inlet line) that last time. Per it's fuel usage curve and the average kw we typically use in the house, it should be down around 0.25 gph.

If you consider that each hour is maybe equivalent to about 25 miles, this would put the 4010 at just over 50 mpg with the Isuzu up around 100 mpg.

I keep a record of the 5 gallon tank fills I put into the tractor and similarly for the Isuzu's 60 gallon tank.

Fuel usage prorates directly with hp on tractors and with # of vehicle on cars/pickups. On cars/pickups with diesel, it's 45 ton-mpg. For a gasoline carbed engine, it's 30 ton-mpg. Newer fuel injected and high C.R. (the Mz3's is 14/1) are up there near the 45 ton-mpg figure of diesels. Turbo will likely boost mpg by around 20%. Any of your carbed tractor or generator engines are gulping fuel at the 30 ton-mpg figure or about 50% more than a fuel injected diesel would do.

Ralph

 

[Diggin It]

Another note to why I was curious as to what others are seeing for fuel consumption is that I was contemplating getting a PTO driven generator.

That's another long running discussion here. My position ... if you have the tractor tied up making power with a generator, what happens when you need it for other more tractor like things ... hauling wood, clearing snow, moving hay, and so on?

 

[oosik]

Almost every spring I thin many of my stands of small pines. 900 to 1200 small( 1" to 6" on the butt) get felled, drug to piles, chipped. I run the Wallenstein BX62S at PTO speed( 2100 rpm) for 30 to 40 hours chipping the pines. I use around 1 gallon per hour during this operation - maybe a little less.

My Wallenstein is connected to my Kubota M6040.

 

[chas0218]

That's another long running discussion here. My position ... if you have the tractor tied up making power with a generator, what happens when you need it for other more tractor like things ... hauling wood, clearing snow, moving hay, and so on?

Yeah I don't want to get into whether or not to get a PTO genny. I wouldn't mind just disconnecting the tractor for jobs around the house then just re-connect when I'm done it is only a 5 minute job and if it is on a pallet and only a PTO shaft it is even faster less than a minute or 2 if it's stuck. My Gas genny uses less fuel but on the other hand keeping gas in good burning order can be difficult. On hand I usually keep around 30 gallons in 5 gallon jugs. That would get me around 5 days of running the Genny non-stop. That should give the towns and gov't enough time to get gas stations back up and running so I can get more gas if need be.

I understand many don't think it is important and probably isn't if you're a smaller farmer or a big, but hobby farmers that are on tight budgets would appreciate this info if buying 1 tractor to do everything.

If I were doing it over (not having any buyers remorse) but I would buy a dual speed PTO so I could run the tractor at lower RPM while maintaining proper PTO speed.

 

[sodamo]

Not a fanatic, but loosely figure 1g/hr for typical use. That figure is just so I remember to top it off before started a project. I do have a use log that indicates about .9g/hr. While the hours are correct, the gallons are often just a guess if pumping from my bulk tank.

As for the diesel vs gas vs propane comment for a generator. More involved. We live off grid so power generation for battery backup is a factor in our lives. Last I checked, I could run my diesel generator 3 hours vs propane 1 hour for about same cost and power produced. Of course this can vary as $/g varies. But the propane generator always burns more g/hr. Haven’t compared against my gas Honda, but maybe someday.

 

[RalphVa]

Propane has only 4.23 #/gallon of energy vs. near 8 #/gallon for diesel, both the same ~20k BTU/# of energy. So, lots more energy in each diesel gallon, and the engine efficiency is also higher.

Our Isuzu generator's fuel usage is low, compared to its prorate from the 4010's long term usage, because a generator sits there running at about 20% or less capacity. For instance, the Isuzu puts out 12.5 kw maximum vs. only an average of between 2 and 3 kw for the entire house.

Ralph

 

[buickanddeere]

Propane has only 4.23 #/gallon of energy vs. near 8 #/gallon for diesel, both the same ~20k BTU/# of energy. So, lots more energy in each diesel gallon, and the engine efficiency is also higher.

Our Isuzu generator's fuel usage is low, compared to its prorate from the 4010's long term usage, because a generator sits there running at about 20% or less capacity. For instance, the Isuzu puts out 12.5 kw maximum vs. only an average of between 2 and 3 kw for the entire house.

Ralph

Depends how efficiency is measured . Per gallon, per BTU ,per dollar or thermal efficiency .

 

[breadtrk]

3037, gallon an hour