Well technically... I do oil it.

Since washing the filter correctly doesn't remove much oil, every 3rd wash, I will VERY LIGHTLY mist a tiny bit of K&N oil on it from a distance. Like making a perfect Martini, simply face towards Italy and whisper "....Vermouth...."


A lifetime of being a professional technician has shown me what happens if it's under oiled (nothing), or over oiled like 99.9999999823% of them are (burned O2 sensors, failed smog tests, rotting rubber, contaminated connectors, choked engines, damaged filters...) so I have come to the conclusion that less is more. I don't think that oiling an air filter is evil, there even are some specific situations I will lightly oil a disposable paper filter as well!

No offense to the OP, but since they weren't able to research that simple answer on their own like a technician would, I assumed they were a do-it-yourselfer type and would therefore act like 99.999999823% of them and think that more is better, so I was just erring on the side of caution. Assuming, that by the time the 3rd air filter cleaning comes around, they should have enough experience to make that decision on their own.