Thanks again. I do appreciate the extensive knowledge and experience responders have been showing here.
I do not know the statistics on when the average consumer trades in their vehicle (at what mileage), but this point may be pertinent to the discussion as well. If most people, as I suspect, have traded their Maxima in before the excessive oil consumption became known, it is left for the second owner to notice, and the factory warranty has likely expired. Another point is that the theorized cause would most often follow standard diagnosed cause and effect lines. Even when the initiating cause may have been the CAT sand or breakdown, it would also be true that the excessive oil consumption is being caused by worn rings.