Hey guys, what about Zinc and Phosphorous? What is their role in motor oil?
Also, besides TBN and contamination, what else do I need to look at in order to know if my motor oil is still ok to use?
Well that sucks. But even if the TBN has some error in it, I'm sure overall it still would show if your oil is good or not. Unless you're towards the bottom where the the error could be the difference between good oil or bad oil.
I would post my wear results but I don't have them. I blew it...
Got my TBN results today from Blackstone Labs. 7500 miles on Mobil Delvac 15w-40 dino oil in the truck in my sig. 70% of those were city miles. Majority of time, engine reached full operating temp on each cold start.
TBN came back at 7.1! Comment from Blackstone:
"The TBN for this sample was...