Does PPM change? If Car #1 had a PPM on average of say 1 or 2 for a certain wear metal, and NOTHING else changes other than the age of the engine, and the same oil is used throught, will the PPM increase in proportion to the age of the engine? If so, at what rate for an Average, and two for a very well maintained engine? Can one tell based on the Increase if there is one, how much life is left within the engine? Anyone have a clue?