From what few oil analysis i have...there is no way to know strictly off the report. Once I mislabeled 2 different oil samples. Doesnt really matter anyway because the term synthetic is just a sales pitch...I love using synthetics too but I am beginning to second guess it all! How can some one spend say $30 for some long drain "synthetic" motor oil and then spend $50 bucks for acouple oil reports so you know if that oil is still good. You wind up with $80 bucks in an oil change and knowing you could have changed that same oil for probably $15 bucks with a top shelf dino and pass on the uoa, just dump it at 5k and save that and change it again. Synthetic mite be "superior" in all aspects but that doesnt guarantee long life of your engine!