I would like to throw my 2 cents in about filters.I dont know how you would check a filters microns but you will be surprised at what you will find if you cut the filter open.Besides finding if your engine is shucking parts you will see how the filter is made.I have cut open hundreds of name brand & found holes,pleats bunched up, not sealed at both ends, paper seals at both ends etc.Have seen off brands that were very good.Company got sued because of the problems of used & new filters that was nothing but a can.They had to eat a warehouse full of nice looking junk. Filters that have metal to metal seals are not the best in some cases-- (example)Cummings had some engines that had a short life with name brand filters- what was happening was the vibration from the engine was causeing the medal seal to come off the seat & let unfiltered oil by pass the filter. soooo checkem out.