I use the cheap 15-40 oil from mills fleet farm. Costs about half as much as name brand conventional oil and I put over 1,000,000 miles on my cat c13 with it. When it was overhauled the bearings, liners and valve train looked fine. Just did the overhaul due to a failed o-ring.
Let me save you some time: go to the chapter on what oil you like, listen to how wonderful it is, and then end the video. 13 minutes and 4 seconds (plus time for comments) that I will never get back.
4:27 "...just make sure to not exceed 2 short intervals before oil change. This will expedite the high solvency of this multi-viscosity oil.." Could you at least have the computer speak correctly