Whelp,
I've been influenced in the past to buy a K&N. Since then I've seen the light, and been informed by the likes of some pretty smart guys. I left one K&N in place until I got another replacement, and today I finally did the deed on one of my cars I don't drive all that much. Now it's ready to drive.
Here's a Purolater versus a K&N. The Puralator has far greater surface area, and it's "all filter". The K&N is mostly wire frame, and actually (in my humble opinion) has very little actual filter medium. It didn't take long after I held the filter up to the sky, and saw lots of daylight, to understand how they get "better flow" (better flow of dirt, in my opinion).
Since I've been with an opinion of my own, so to speak, about the K&N, I decided to "put my money where my mouth was", and I decided to burn the darn thing. Are we ready? Here goes.
Yes, this was a satisfying thing for me. It was also a "learning experience" too. After the K&N was totally torched, guess what? Most of it was still there. It's almost "all wire frame". There isn't much filter medium there, guys, it's all wire armature. I held the dirty filter up to the sun before burning it, and sheesh, I could see right through it. Therefore, I stand on my opinion that the K&N will admit more dirt into my expensive motors than the stock filter would, and since Porsche didn't go brain dead when it came time to size the air box and specifiy the filter, I really see no need (now that I'm older and wiser) to spend more and get less. If you can see through the K&N filter, it doesn't take a rocket scientist to know, driving through a dust cloud near a quarry, or driving on a dusty dirt road, would be putting a LOT of silicon into that motor.
Afterwards, I fired up the little bastard, and took a ride. Guess what? I didn't notice any difference in performance at all, nor did I expect to.
It's your car, your money, and your choice. You saw my choice. Here's a relevant thread
http://www.network54.com/Forum/426130/thread/1128071541
Regards, P