The only thing I disagree with is, it could be used to detect other issues that aren't issues yet, like a slight coolant leak, but like you said, you want to see trends moving in a positive way for life, age, and to spot potential issuesWELL beyond the useful resolution of a $20 UOA. Accuracy here is not in the single PPM range, UOA's are a tool designed to identify contamination and determine suitability for continued use, not discern the minutiae of wear for the purposes of evaluating lubricant performance. It's like using an industrial pile driver as a framing hammer, it simply lacks the precision to perform the application in question.