Anybody else running my equipment stopped when I observed my neighbor's hired help keeping my tractor at max rpm idling in place. They were working a drainage project and couldn't be bothered to idle down when they got off the tractor for a few minutes.
I run at about 80% max, moving up when I need the additional power. I don't need to burn the fuel or shorten the engine and pumps' lives at higher RPM than is necessary to do the job. I turn the idle down when doing low or medium speed tasks.
I've asked the Engineers (Design & Service), the dealers, the dealer techs and local operators. None can provide a valid technical reason to max out the RPMs all the time, but most operators max out the throttle right after warm up......because it's not their machine. They are not concerned with the service life or cost. Their focus is work completion rapidly....check out the rear of every jobsite SSL, MTL/CTL and excavator for the results of this focus.
That tells me that the engineers aren't doing much testing.... (which isn't much of a surprise - and some times it's intentional if the design and testing responsibilities are divided in the organization for design quality/verification reasons).
Have been party to the testing of multiple engines (to include some diesel engines) for aviation applications, I've seen that frequently the real killer of engines is rapid/frequent throttle changes (i.e. not letting the engine run at a consistent throttle setting). An engine left to sit running at a consistent throttle setting close to a design point (usually above idle) tends to last far longer than one where the throttle is being banged around extraneously (which I'd wager most tractor owners don't do) -- and if the throttle is being jerked around at rates faster than the engine (or it's turbocharger) can even respond to the changes it can destroy an engine in very short order. Saw that last situation play out as a result of software engineers being in charge of controlling the engine throttle as part of controlling the vehicle as a whole ---- despite they're having zero experience with turbo-charged diesel engines.
Of course, that's just for the engine ...other parts of the system can be affected differently. So at an assembled system level it really depends on how all the parts were designed, assembled and work together (or against each other) as to whether mechanical wear or purely mechanical fatigue or thermal fatigue is the more damaging problem.
Which brings up the reality that most of the time when engineers are designing something they're are designing/optimizing for a few pre-selected operating points, rather than ensuring operating characteristics for the entire operating range (which is how situations like oil pumps potentially not pumping sufficient oil for the engine at idle speeds arise).
The other part of that is the engineers working one part of a complex system generally don't interact with the engineers designing other parts of the system (even if they work for the same company) unless they have specific requirements to do so (e.g. transmission interfacing to an engine). Of course that's in a well run organization, in a poorly run organization the engineers working different parts of a system may start making assumptions about (or just ignore) what the engineers working connected pieces are doing to design their respective parts of the system.
All that being said engineers working on a project are generally the last people anyone should want writing an operator's manual ...and that's speaking as an engineer.
If a company wants to have a good manual, at a minimum it will likely be written by a technical writer with some input information from all the various engineering groups (mostly to capture operating limits, technical specifications like fastener torques, and maintenance intervals), as well as have a user & maintainer validation process to make sure that the manual as written actually makes sense from a user & maintainer perspective. .....all of which isn't cheap to do.
So if/when the end user isn't likely to read the manual -- or have the quality of support (to include quality of manuals) play a part in purchasing decisions......
