Reviewed By Jack S (Kearney, MO) Reviewed for a 2011 GMC Sierra —2/11/2016 8:16 AM
Noticed quick throttle response right away. Had to modify the L shaped mounting bracket for the air box.The front bolt that holds the top on the air box needs to be tweaked, you can't get screwdriver on it because of the finder well. I put the bolt in from the inside and put a wing nut on the outside, worked great. Very satisfied with product. I don't know about mileage increase I haven't driven it enough to tell.