I put a K&N on my truck I also removed the screen before the air filter box and don't forget to remove the positive cable for 5-mins so the computer can reset and re-learn the new air-fuel mixture. You will hear and feel the difference. Remember more air means more gas and less miles per gallon! (OUCH!)
first of all you wont notice much if any difference; seat of pants difference takes more than a 2hp increase. secondlyin response to the guy above dont you think engineers spend countless hours do making sure that the stock paper element isnt restrictive and how will there be more sound? thirdly it will use the same or less amount of gas until you floor it all the time naturally the milage is most dependant on the driver
yea more air means more gas, but your only going to get more air if your accelerating harder. The K&N filters simply make air flow less restrictive, and thus more efficient. You will see nothing but improvement. However, k&n gets expensive. A k&n for my car costs about 180 plus shipping, and i got one off ebay, just a s good, for 70 shipped