Anyone experienced an advantage in HP, Torque, or MPG by installing a high flow air filter kit (K&N, Airaid, AEM, etc.) on a 4.0L? I'm getting a '00 Cherokee Sport soon and was looking at my options. Is it worth the $250?

I installed one on my 91 XJ. Seat of the pants tells me that there is a slight increase. Of course I have a bored out throttle body as well. MY MPG has gone up by 1.5 miles. Only slight drawback is a slight whistle when you hit the skinny pedal.

i installed one on a 4.0 94 xj,its not what they claim as a big increase in pwr,put the jeep on a dyno,it came out as 2.7 hp,not enough to feel it..it did increase milage by 1.2 mpg..you call the ball @ $250.00...if you decide on the k&n fipk, reset your computer by disconnecting the positive on your batt.for 20 sec.it will reset your fuel/air & other computer related items....good luck!