I have been to the K&N filter facility in Riverside CA it was about about 5 years ago, they do test all there products, most people that knock then have never had one IMO. They are a cotton layered oiled filter, they started back years ago for off road racing, if your getting oil in your intake, you didn't oil it correctly, they have instructions, if your getting dust in your intake you didn't oil it correctly. I have a Banks Intake on my 05, it has a cotton oiled filter just like the K&N, I use K&N oil on it, my intake is spotless, and there is no oil on anything, my 55 Chevy street rod has a K&N, same thing there, when I had my airplane, a Beechcraft Bonanza, it had a K&N, no problem there, so you can knock the K&N all you want, but if you never owned one, try to stop repeating all the conversation you read on web sites, it isn't true. Now with that said, the factory paper filters do a fine job, and when I get my 2012 Ram this year I will not be installing a K&N, because for what I will be using the truck for, I don't need one. I don't do oil testing on my truck, but when I had the airplane I did, and after adding the K&N air filter, the Silicone (dirt) in the oil was reduced, the stock paper filter looked like a car filter, 5x12, and about an inch thick, that is my test, it helped, I like there filters, but you have to have the right situation to require one.