I'm not so sure I would consider 5-8 microns big stuff, a 10 micron would be considered more than adequate in an industrial hydraulic system, with 25 micron being fairly common, 5 micron would be considered overkill, you can get 2-3 micron filters but those are for extremely sensitive systems. you have to keep in mind a micron is one millionth of a meter, there is 25.4 microns in .001 inch, at the very least you should have .002 clearance in most parts of the engine, even luberfiner which is used as a bypass filter (mostly) only bothers to document down to 5 microns. I'm not saying cleaner isn't better, but at some point you will be creating an incredible restriction in the system, I'm not sure how many microns an oil molecule is...thats the best part about lubrication, there is so many ideas and opinions surrounding it people can banter back and forth till #@#& freezes over, snd still come no closer to a conclusion than when they started.
