Originally Posted by Jordo!

Oiled cotton or synthetic dry works best, with slightly better flow on the oiled cotton at the cost of some filtration (slightly better for the dry). Both should flow and filter better than paper, so no worries.

Foam filters suck. The HKS is a foam filter.

I too just sell off the old for someone else to clean and purchase new ones. Less of a hassle.

based on my UOA's, which also measure particles that indicate poor air filtration, my K&N's work well.