I'm not an engineer but,it's clear to me that better flow would always let more dirt particles thru! Without even testing.K&N even states that. The recleaning of K&N filters done incorrectly would make them flow worse than new paper ones! I did price the Stock filters only at the dealer and they were the same price $30 ea. as the new K&N at AJUSA.com. But they're probably half that much at a parts store.