Re: Sustained RPM\'s
I've a Benz diesel that's 22 years old this year. We regularly rev it to the limit in 1st and 2nd gears: approx. 4,400 rpm. It's designed to run at maximum rpm all day long. Many do on the German Autobahns or similar roads in Italy and other countries. I know. I've been passed by them, me at about 80 them at about 95.
My 4010 maximum rpm is about 3,000 rpm. Think the 540 rpm PTO is at 2,900 rpm. I have NO problems with running at this speed all the time as long as those screens don't get plugged with debris. On my 4010, there're the outside screen plus another in front of the radiator that need to be cleaned periodically.
Small engined Volvos and Benzes typically go 300,000 miles or so between overhauls. Volvos typically won't even start using oil until around 300,000 or more miles. Some have been overhauled and have seen over 1 million miles. It's not the engine speed (higher in 4 cylinders on cars). It's lack of maintenance that kills them, or driving at too low an engine speed for the load. You can kill an engine quicker by lugging it than by revving it.
If you start your tractor in a garage that never gets below around 50-55 F, you really don't need to idle it that much when cold before proceeding with heavy work. Even if stone cold, I'd only follow the manual's recommendation of about 5 minutes.
Ralph