IDK what the percentage is, but one of those sites, might be the one you lsited the dude said that in microns that the K&N and Mobile 1’s fell short of ones such as purolator
thats all IIRC… im only 3 hours of sleep for the past 2 days so I might be wrong… but there was some exspensive filter that filtered about as good as a pair of fishnet stockings