I have one on my Jeep. I don't know how much improvement it has made but it looks good. I have had a K&N filtrer on it for 3 years. I like having the filter up high, helping to keep water and such out of the motor. You will hear a high pitch noise at certain speeds, it is only the the air racing down the tube and nothing to worry about. It goes away with increase of decrease of speed. The tube is about the same cost as the factory plastic one, and is made up of several peices of tubing welded together. I was supprised by that. I was expecting seamless for some reason. You cann't see the seams in the picture. It doesn't effect how it functions and is better than using just the rubber elbow like I was . Bottom line is it has to be better than stock YJ because you eliminate the air box at the grill.