People obsess over oil WAY too much.
Use a good brand of engine oil that meets the specs for your engine.
I just dug out my Cat 3116 engine manual that came with my 1991 bus. If you really want to get anal about it the manual recommends that you use only Cat oil that you can buy at your friendly local
Cat dealer. Probably at a price nearing the price of a gallon of Starbucks coffee
The next paragraph states that if you must be an idiot against all of their well thought out marketing recommendations you can use API specification CD,CE/SF or CE/SG
I personally for years, have been using what ever diesel oil was the cheapest diesel oil at the local farm store with no ill effects. Last semi had 1.5 million miles on it when I retired. We did pull the pan at 900,000 to have a look see at the bottom end and put the bearings back in.
I'll sit back now and enjoy the show.