Originally Posted By: 1JZ_E46
Originally Posted By: zeng
Very good metal wear rates.
Cu and (part of) Al likely comes from cooler, not bearing.
This C3 oil of TBN 7.8 drops to 2.2 over 5100 miles, which I interprete as good TBN retention.
I won't look at TAN , if any, and agree with BStone OCI could be extended further to 7000 miles or probably beyond.
Edit:The test of the pudding is in the eating, which in this case refers to (the very good) Fe wear of 5 ppm over 5100 miles.
Wear metals ppm is only a piece of the story. You will not see deposit formation in a UOA, which you get from low TBN or where TAN is higher than TBN.
Deposit formation,contents of Na,Ca,Mg etc, sludge,varnish,low TBN , high TAN,residual KV@100*C, fuel dilution % etc are merely/strictly noises.