If an analysis shows consistently that the iron is 30 ppm and the chromium is 6, lead 20, copper 20 and silicon 18 etc.etc., after consistent oil changes of 5000 miles and the engine now has 60,000 miles we do not know how long that engine will continue to run fine without making any changes or locating any air leaks but just keep on running it as is; as opposed to changing that oil at 3000 miles finding air leaks and having lower numbers. As many many drivers today don't care about oil and could care less about these discussions and yet they get 100,000 miles regularly out of their engine. So, will the high numbers if unchanged result in that engine blowing or consuming oil at 100,000 (unlikely) but can it go 120,000, 150,000 or 200,000 with the same high numbers and no change in oil intervals? We don't know; yet we continue to put forth a huge effort on these boards, spend a large amount of money on products to achieve that elusive goal of ??????????? It would be great to know that hey, if you get 30 ppm of iron consistently for 60,000 miles your engine will be history by 100,000. That would be valuable info! Too many variables I know but hard core data and science sure seems to be lacking from the engine manufacturers, lubrication industry and scientists in the field. As a side note I have one engine with analysis since new that has 15-30 ppmn of iron, silicon in the 20s consistently at every analysis yet has 147,000 miles and running well. Go figure.