The cars and farm truck gets the same treatment. Lubricants are cheap compared to a rebuild and oil analysis lets yo know that all is well inside the engine.Very interesting.
Given the amount of fluids (translation...$$$$) your big tractors use, I'm sure the data you get from the analyses is well-worth the cost....Maximize fluid life/efficacy, but not beyond....
One thing I learned a long time ago is, buying in bulk always costs less with lubricants and greases, so long as you have the capability to dispense them.
Like my grease. I buy 150 pound open head drums of grease and fill my hand grease guns with the bulk greaser. Lots easier, less messy and much cheaper. I use synthetic grease with a high pour point because it needs to stay on when in the field.
You'll pay a drum deposit but that comes back when you turn in an empty drum and most suppliers will deliver too and to a lesser extent, keeps the plastic jugs out of the landfill.