Actually, they don't claim a rating of 99% at 25 microns. They claim "99% Multi-Pass efficiency and removal of particles as small as 25 microns". If challenged, they could back up that claim by showing that they ran an oil sample through the filter, say, 1000 times and sure enough, got 99% the particles out of the oil, including a couple that were "as small as 25 microns" once the filter was sufficiently plugged up. The wording reeks of marketing weasel wording. The "Product Specification" section is probably off of their spec sheet from the engineering department, doesn't have any weasel words, but does omit the percentage blocked in the micron range given (42 - 60).
This is eerily reminiscent of what I uncovered recently regarding the Purolator Boss. They had a very similar disconnect between their spec sheets and their website marketing claim. When I challenged this at to the top level of the company, they admitted that the spec sheets were the correct numbers:
https://bobistheoilguy.com/forums/t...ashlight-test-in-canister.386911/post-7125977
PG's apparent solution to the problem is simply not to respond to any inquiries.
I am wondering how widespread this slight-of-hand is being practiced in the oil filter industry ...