Wines, at least some of them, improve with aging. But motor oil is more like our good buddy beer. Once beer leaves the brewery, it's all downhill from there. Same for motor oil that's poured into a crankcase.
As for "dirty oil filter media filters better than new," that's essentially the K&N air filter theory, and it's correct. (I find the concept of "dirt prefiltering out dirt," while true, to be very amusing.) At the same time, "more dirt" is a ten dollar word for "gradual clogging." K&N air filters actually have sand-sized holes in the media -- next time you stop by a parts store that carries them, pull one out and hold against the store's overhead lights. Looks like stars on a dark night. Oil filter medias are much finer, and have also improved from 35-40 micron filtration in decades past down to a typical level of 20-25 micron filtration today. I suspect any modern, quality oil filter will perform very well when brand new, with no accumulated "dirt prefiltering layer" necessary for optimum filtration. And I suspect that the "very dry start" wear realized when installing a new, unprefilled oil filter is insignificant when compared to the total dry starts over even a short 1,000 mile oil change interval, let alone 5,000 miles.
[ March 08, 2004, 05:08 PM: Message edited by: TC ]
