I just replaced mine with a new one at 9000 miles. That was the dirtiest air filter I have ever seen. Ill spend 40 bucks for a new cone filter every 6-8 months, no biggy. I tried cleaning them on my cobalt, but felt i didnt do it right. Either was under soaking or over soaking when putting new oil on, so I just decided id buy them pre oiled and call it a day.