I installed this about a week ago and so far I can't say I have noticed any significant differences. My car displays MPG and it has not changed. Sounds like it has more guts of the line but I think it's just the sound giving you the illusion of speed. If I notice any changes I will change or modify this review.
5th AIRAID System I've installed on my families vehicles. This one was more difficult to install because of the tight clearances under the hood of the 5.0 Mustang (If you install on a 15-17 GT secure the air box last). This system does look and sound a lot better than the stock Ford intake and the car seems to have more power and better acceleration but I can't prove with out a dyno. Highly recommended for you Mustang 5.0!