We have never lost an engine due to oil or filters,--Let me correct myself. Since I have been with this company {15 plus years and have seen 186 different tractors owned by the company}
we have never lost an engine except one that was just inframed by the dealer {A series 60}. Now with that said I'm the one that keeps track of services and repairs on 60 tractors and 96 trailers.
Which gives me 156 engines to monitor. Series 60 engines oil is changed every 15,000 and greased every 7,500 on a short service, DD15 engines oil is changed every 30,000 and greased every
10,000 on a short service. Maximum over run on a service may hit 2,500 miles. But the real key to keeping a engine alive is the older it gets and more miles it gets to slightly shorten the
service intervals. In the shop engines after 550,000 miles like the Series 60 I change at 13,500, DD15's at 27,000.
But the big factor is set a realistic interval for services and stick with it, not to mention all the other things that need attention on a regular basis. Like belts, dryer cartridges, air and power
steering filters, the list goes on.
One thing I always tell the boss {everything stars with the shop not the office} if the equipment don't roll no one needs to come to work!