Recently I ordered and installed this K&N 63 series Air Charger (63-1552) in place of my Patriot's factory airbox. The factory air box was shown to be a major performance bottleneck. I thought I was not going to notice much of a performance improvement over the K&N drop-in rectangle filter, which gave me another MPG or 2 over paper. I rather enjoy the modest growling when I must accelerate hard ;-P. If I have to get a couple components cleaned every 40K miles or so, so be it, I'm getting another 4MPG over factory and a very pleasing response, engine is much quicker to respond to the gas! I drive 60-80 miles a day in mixed traffic and wished I had gone to a CAI years ago. Installation was relatively easy with clear, illustrated instructions, though a flex/ratcheting wrench would have made a couple tight spots easier to work the bolts.