Originally Posted By: JerryBob
Isn't that the purpose of Blackstone's universal averages?
To a point, but how accurate are their delineations between different submodels and engines? In any case, comparing single digit PPM to single digit PPM averages with an unknown error bar in a single, one off UOA is a mathematical Charlie Foxtrot. Nothing of any value whatsoever can be determined from this. Without TBN (or other markers of similar use), it's exceedingly difficult to decide whether or not the lubricant should be condemned (unlikely given its low mileage).
So, we're trying to use a UOA for a purpose for which it isn't designed, and worse, doing so on a single UOA. And for the real purpose of a UOA, to determine the suitability of the oil for continued service, none of the usual tests (TBN, TAN, oxidation, nitration) have been conducted. So, what's the point?