Ok I got my oil sample reports today via email. I sent in 2 samples. One was virgin 15W/40 Amsoil to establish a base line. The second one was a sample on this oil which is in my truck with 8,910. 4 miles on it. Their comments are quoted below. When these samples were sent in the truck had 148,855 miles on it. I am now over 150,000. Next sample should show what the spinner is doing. If I can figure out how to attach a spread sheet, I can just post it with all the numbers and such.
Virgin Sample
"Nothing unusual showed up in this sample of virgin Amsoil 15W/40. The additives were normal for Amsoil. No wear metals were present, which is great. We are increasingly finding traces of metals, perhaps from holding tanks, in virgin oil samples, though no metals were present here. The TBN read 11. 8, so you're starting out with lots of active additive. No moisture present. The trace of insolubles probably shouldn't be there, but it's not really hurting anything either. This is serviceable oil. "
Same oil with 8,910. 4 miles on it.
"You mentioned you wanted the virgin oil sample to serve as your first sample, so we put them both under the same unit ID. If you actually wanted them to be separate units, just let us know. Your Cummins engine looks great at this point. Wear levels read well below universal averages, which are based on a 6500-mile oil change interval. You ran this oil almost 9000 miles, so you're getting much better wear after more miles--a sign of a great engine. The TBN read 8. 3, lots of active additive left. Note the high viscosity, which isn't hurting anything. Try 10K next. "