Hi range or low?

[Dick]

Your RPMs can stay at the same level and you could be over-straining your engine as it begins to lug. You should backoff on your speed (not RPM) to avoid straining the engine.

 

[W5FL]

Dick,

My tractor is a gear tractor, but if the Engine is running at PTO speed, I will run in the highest gear that doesn't try to joust you off of the tractor for mowing or pulling a spreader. Run slow with the bucket full. If the engine speed falls a little, I give it a little more throttle. Sure don't understand what is wrong with that. Now if it won't run PTO speed at full throttle, then I agree it is in too high a gear. Never considered that you could strain an engine or gear train. That's what they were made to do. /w3tcompact/icons/smile.gif Never had a hydro and I am sure they are different.

 

[Anonymous Poster]

You might wish to look at a Texas A&M publication online about Tractor Energy Conservation. Even though it was written addressing a geared tractor instead of a HST, I am sure some of the principles are the same. http://agpublications.tamu.edu/pubs/eengine/l5085.pdf

 

[W5FL]

Interesting article. Thanks for the reference. John Deere tried to capitalize on that by offering a Economy PTO on their 10 series tractors. The dealers said they never sold any of them and I did not find one anywhere I looked. Kubota does not offer it, but you may figure out that if you can put a 1000 rpm PTO gear in and operate the engine speed correctly to get 640 rpm, then you have the same thing. I really think that was what John Deere designed, but marketing figured out that no one would buy it for 1000/640 so they changed the name.

Most PTO speeds are 80-90% of max hp speed, so they get some (but not all) the benefit of reduced speed to conserve fuel. Many of the newer Kubota engines seem to product remarkable fuel economy at PTO speeds. /w3tcompact/icons/smile.gif