I put one on my truck this weekend, and have 400 miles on it since install. I have averaged 19 mpg, which has been mostly highway, per the vehicles info system (which I know can be off at times). The sound is great when you put your foot in to it. I have had other brands of CAI's, but I keep coming back to K&N. Install took about 30-45 minutes, and it does seem more responsive. The rubber grommets hold the lid pretty tight. I didn't feel uncomfortable with it. I have a 19 Denali with the 6.2L. Hope this helps.
