I'm not going to get into a long battle as far as which Performance AIK is better blah blah blah..What I am going to say though is that there is a HUGE difference going from a Performance AIK back to the stock air filter. I had recently sold my performance AIK to someone that wanted the one I had. Well, of course, I had to revert back to the stock air filter until my other AIK came in. I tell ya' what. It was almost as if I had extra weight in the back of my HHR when I put that stock filter back on. The engine felt almost sluggish. I think I even heard the engine cough and gasp for air at one point. I could tell a bit of a difference when I put my first AIK on there, but the difference was even more obvious switching back. I received my other Performance AIK today. Just in time. I installed it and my baby was purring like a tiger. Took her out on the hwy to celebrate and Bam! She was off. It was if I had installed a new pair of lungs.

Moral of the Story Is: If you sell your Performance AIK before you get your other AIK in, you're better off walkin' rather than sticking that stock air filter back in.