Full RPM or high idle? Bush hogging fuel efficiency

[JoeBuyer]

What gives you the right to call the honest replies of other posters ridiculous???

Pretty high and mighty... I guess not much changes!

I am not sure he meant anything by that.

I find it interesting that often when there is an argument amongst knowledgeable people it is because there is no clear answer.

 

[RDrancher]

Now that I've managed to quit laughing at some of these ridiculous replies, I'm gonna take a stab at this!

I own a commercial mowing business. We mow approximately 15,000 acres a year. Just to pass the time, I've had operators experiment with different mowing techniques. One is varying throttle and ground speeds. FIRST and most important variable is ground speed. That determines quality of finished cut AS MUCH if not more than blade speed. There's a sweet spot in the speed range where safety, efficiency, and time spent reach their zenith. Several of the tractors we use have IVT transmissions. Ground speed can be varied with little regard to engine speed. Then we try to establish an engine/pto speed that gives us the best fuel economy in conjunction with a suitable quality of cut. With a total of 16 tractors, of which there are 7 different models/brands, we've established there is NO hard and fast across the board "rule" that applies to every one. Mowing conditions also need to be taken into consideration.

OK....Bottom line....in SOME cases, running engine UNDER rated PTO speed is more efficient. In SOME cases, running AT rated rpms is most efficient. And in ONE instance, running ABOVE rated rpms gives us the best results. Long story short...No set answer.

SO....IMHO, which is based on (literally) 10's of thousands of hours under the gun, the best I can offer is, "it all depends".....

My opinion? Try several throttle settings over time and see what works best. Don't throttle down so low as to labor the tractor beyond reasonable limits. See what happens.

Just for argument's sake.........One particular tractor I own, by running 250 engine rpm BELOW rated PTO speed, saves around 12 gallons of fuel per 8 hour day, while accomplishing the same amount of acreage in that time by adjusting gearing up to maintain ground speed. That's a 140hp tractor with a 20' batwing, mowing in dense grass/weeds approx. 2-1/2' tall. YRMV

Bill

Thanks Bill. Interesting results.

 

[JDgreen227]

What gives you the right to call the honest replies of other posters ridiculous???

Pretty high and mighty... I guess not much changes!

Concur...while I do appreciate Farmwithjunk's input, I query his "example" of a 140hp tractor with a 20' batwing mower. HOW MANY of the members here use and have such an extreme example of a mowing tractor? What a RIDICULOUS reply...how is a 140 hp tractor's fuel usage applicable to the owners/members here who use a machine with 20-30 PTO hp?

"Approximately 2-1/2' tall...." sorry, that is not precise enough....to give real input the grass and weeds have to be EXACTLY 2 1/2' tall in each and every usage situation. Otherwise your example is simply RIDICULOUS as the height of the grass and weeds have to be the same for comparision purposes.

Not trying to bash you but I really do think you have no valid reason to say others here have "ridiculous" replies.

 

[Soundguy]

i dunno.. I know some of us here mow with 95hp tractors and 15' mowers... that's 'close' anyway..

 

[Martian]

Concur...while I do appreciate Farmwithjunk's input, I query his "example" of a 140hp tractor with a 20' batwing mower. HOW MANY of the members here use and have such an extreme example of a mowing tractor? What a RIDICULOUS reply...how is a 140 hp tractor's fuel usage applicable to the owners/members here who use a machine with 20-30 PTO hp?

"Approximately 2-1/2' tall...." sorry, that is not precise enough....to give real input the grass and weeds have to be EXACTLY 2 1/2' tall in each and every usage situation. Otherwise your example is simply RIDICULOUS as the height of the grass and weeds have to be the same for comparision purposes.

Not trying to bash you but I really do think you have no valid reason to say others here have "ridiculous" replies.

It's all proportionate. He stated himself it all depends and gave an example that showed one way. I'm sure other tractors act differently. I really appreciated his input even if it wasn't 100% precise, I really don't expect the man to go out and measure all the pieces of grass and find the average, just to share with us.

 

[JoeBuyer]

..HOW MANY of the members here use and have such an extreme example of a mowing tractor? What a RIDICULOUS reply...how is a 140 hp tractor's fuel usage applicable to the owners/members here who use a machine with 20-30 PTO hp?.

Our 100+hp "mows" more than any of the other tractors. If just hogging some brush or weeds of course our little 45 HP comes out. While I agree he probably should have used some different language to refer to other posts, I appreciated the real world reference including a 100+ machine. I think the original question can apply to more than a brush hog.

 

[TripleR]

I don't much care for the "ridiculous" comment either, but Farmwithjunk is not known for his tact or gentle treatment of other members, know from personal experience, but he provided what I thought was pretty good information based on his experience; whether it's relevant in our case is up to us, like everything else we can take it or leave it.

 

[BlacknTan]

I don't much care for the "ridiculous" comment either, but Farmwithjunk is not known for his tact or gentle treatment of other members, know from personal experience, but he provided what I thought was pretty good information based on his experience; whether it's relevant in our case is up to us, like everything else we can take it or leave it.

He may provide information relative to his experience, but shouldn't we treat others in the manner we would like to be treated ourselves? Others here are not idiots, and don't deserve to be treated as such.

Deal with others on the internet the way you would in a face to face conversation...

 

[TripleR]

He may provide information relative to his experience, but shouldn't we treat others in the manner we would like to be treated ourselves? Others here are not idiots, and don't deserve to be treated as such.

Deal with others on the internet the way you would in a face to face conversation...

No argument there, but I have learned through some not so pleasant exchanges with him and others to try to separate information from personality; much easier on my health.

I have posted ad naseum on the need for civility, but as hard as it is to believe, not everyone listens to me.:laughing:

 

[BlacknTan]

No argument there, but I have learned through some not so pleasant exchanges with him and others to try to separate information from personality; much easier on my health.

I have posted ad naseum on the need for civility, but as hard as it is to believe, not everyone listens to me.:laughing:

I listen to you... LOL

It would be nice if we could just post our thoughts for others to accept or not, as they please... And leave the thoughts of others alone. We may not agree, but that's what makes the world go 'round!

I've yet to meet the person that has the ultimate grasp of "all the answers..."