Just because one person got by 19 years without changing coolant doesn't mean the next person will. That is the same with a lot of the maintenance items. I was surprised, however, after retiring from Caterpillar early and taking up farming at how frequent the service intervals are. Construction equipment users will not tolerate that, at least not Cat's customers. An example is hydraulic oil - with my last machine series I was able to increase hydraulic oil change from 1,000 hours to 2,000 hours, 4,000 hours if testing the oil at 1,000 hour intervals. Engine oil - 250 hours wasn't good enough so with filter improvements, improved oils, and a slight crankcase increase we got that up to 500 hours. Coolant, everything leaves the factory with ELC, extended life coolant good for 5 years. What is so different? I do know that at Cat we filter our hydraulic oil to a cleanliness much better than that of my Kubotas. But one unexplained item is that now Cat uses Kubota engines and uses Cat's oil change interval instead of Kubota's. Surely the same engine in a Kubota compact track loader can't see all that much higher duty cycle than it does in a Caterpillar compact track loader.
But then again realize that service intervals are educated best guesses. When a machine is released for production none of the test machines have ever run to the end of life. At Caterpillar every machine worked on by a dealer, in or out of warranty, is logged into the system giving a tremendous amount of data with which to work, and we have tools to analyze all that data.
As for my largest Kubota tractor, fluids have been changed by the book and samples go to the Cat dealer whose system keeps track by serial number even though it is not Cat. All samples have come in green with the comment that no wear metals above usual found, continue to service at recommended intervals. That is boiler plate for they're covering their *** not saying I should extend intervals but nothing is wearing, it's barely broke in.