low RPM

[nwltruck]

Just wondering .......... I have heard that it is harder on the diesel engines to run them under load at a low RPM.(work not requiring 540 PTO) Is this just turboed engines or all diesels. What damage would I be doing to my CUT.

 

[GaryM]

I have a JD 4100 diesel and will often mow, if the grass isn't too heavy, as well as use the FEL at 1500 to 2000 rpm. Never noted any issues. I will run at PTO speed if the going is tough and I think I need max power.

I await the experts weighing in.

 

[Andrewnewy]

It's bad if that is all you do, but ideally you should pick the rpm to suit the task, you want the engine under a bit of load, but not straining to keep up. There is no point running at full rpm if you don't need it, all your doing is wasting fuel. Same goes for PTO, just because it can run at 540rpm doesn't mean it has to, often tasks like mowing, slashing (bushhogging for those in the US) spraying don't need more than about 480-500rpm but once again this comes down to what your trying to achieve.

 

[bigbull338]

when i use my tractor i run it 1500 rpms just driving.when im working the tractor i run at 1800 or 2000 rpms or more depending on what im doing.to run at 540 you need 2700 rpms.

 

[Denwa]

Just wondering .......... I have heard that it is harder on the diesel engines to run them under load at a low RPM.(work not requiring 540 PTO) Is this just turboed engines or all diesels. What damage would I be doing to my CUT.

According to the folks at my Kubota dealer, diesel engines, particularly the smaller ones, AND including the hydraulic pumping system, are much happier
running at higher RPM than at lower. The faster the engine/pump is operating, within red line of course, the less strain on the systems.

Fuel consumption will be a bit more, but which is less expensive, fuel or repairs? Same reason a car/truck engine is happier if one downshifts when going up steep grades.

Me, I keep the RPM up when using the implements..

Regards,
Dennis (WA)

 

[nwltruck]

I have have been mowing at 2000,and doing loader work at 1100 to 1500. Just seems to me that the little thing is really screaming at 2700 to get 540 PTO when I snow blow. Thanks for the info and opinion. Sounds like I'm doing what I'm supposed to.

 

[whodat526]

it is not good to run it at low rpms in the long run because it will start slobbering oil and smoking

 

[Soundguy]

lugging is what you eed to be concerned about. don't lug them.. otherwise running a hair low on rpm isn't usualy a huge deal unless you are using an implement that specifically needs a set rpm for power generation.. or some pump flow that is being utilized.. or a broadcast spreader that relies on rpm for spread width.. etc.

soundguy

 

[Gary Fowler]

We ran our farm tractors for hours at a time cultivating when the crops are small and you dont want to go too fast. As long as the engine is not lugging down, low rpm wont hurt a thing. There is no difference in locking your cruise control in on your diesel truck and running for miles and miles or any other engine. Cars are built to down shift when needing more power and if you watch you loading of the engine, running at around 1500 RPM or higher is not going to hurt your tractor. Anything less than that might cause a little carbon build up in the exhaust that will blow out as soon as you rev it up.

 

[TripleR]

Like many, I run my engine appropriate to the task.

I usually don't go below 1500. I usually run my PTO equipment at or close to 540, but for years ran our 60's model Case and cutter at what "felt right". It is still running strong and never has had any repairs.

I am no different than many in that maybe I tend to over think some of this stuff. When I was younger and did this for a living so to speak, I operated more by feel than anything else.

I do accept there are parameters beyond which we should not go, but they may be broader than some of us think.