Thanks for the VOA. I’ve used plenty of this oil in the past few years and it’s one of my favorites.
Looks like it’s still on the thicker side which is nice.
You picked a winner, especially if you're finding seepage or minor leaks.
The truth is, my engine does not use, leak or even seep oil. I'm just trying something different after about 35k miles (3 OCIs) using Castrol Edge.
Seems like a really low tbn for a synthetic high mileage oil. I think Edge is in the 11-12 range per PQIA.
When PQIA gets their analyses done, their lab uses ASTM D2896 just like the oil blenders. My lab had always done so as well, but this VOA was done with ASTM D4739 and that's why it resulted in a "weak" looking TBN.
ASTM D4739 (used for UOAs) only shows the TBN of the metallic additives. It doesn't include the ashless detergents that are also in the oil.
ACEA A5/B5 requires a minimum TBN of 8.0 using the D2896 method and I suspect that this oil would be well above 8 if tested by PQIA. For the record, Blackstone also uses D4739 for both VOAs and UOAs.