I wouldn't touch K&N. The filters get better as they get dirtier. I had a buddy that built a box with a vacuum under it with a screen. He set a cotton ball between the screen and the filter. Turned on the vacuum with the K&n filter mounted to it. It was my filter from my truck had about 6 months of use on it. We mounted the filter and sprinkled some light dirt over it. I thought for sure the filter will perform. The cotton ball was brown. 80% of the reason your oil is dirty is from the filter. I have the air intake kit on my chevy, I've since swapped out the filter for Amsoils filter mounted to the tube. Did the same test after 6 months of use the cotton swab was still white. K&n aren't that good