Think Cat bought part of Perkins, maybe 100% of it, I do not know.
I put 6,000Hrs+ on a 1.5L 3 cylinder Perkins (Prior to Cat), no issues using 15W-40 Rotella, now have the Power Tech 12kw Kubota 4 cylinder with only 2,100 hrs, same luck, just a perfect runner, Oh yes, I change about every 150-200 hrs 5 qts also to the 10 gal in the ISM500 about 5,000 miles. We purchase oil by the pallet, usually 4 at a time, so not a major issue to change oil in the babe.
Not a cutesie operator, see zero reason to buy snythetic, must be a feel good thing ?
I run 10w30 synthetic in the Rigmaster on my truck. It is an old one so it has the smaller blue motor, 400cc IIRC Perkins. Never mind that an engine will last as close to forever on synthetic as is possible for a machine, the biggest reason I use it is that at -20f it will roll over quick enough to fire up without an argument and instant oil pressure. Ordinary winter day it spins like summertime. Conventional 10w30 oil in those conditions was a real groaner on the starter and the oil light took forever to go out.
Can you tell I'm a believer?
Why do you only run 5000 mile oil changes on that ISM? Seems about 7-10,000 too soon.