I have one. I definitely notice a "difference" from stock.. In fact, recently I put the stocker back on a drove it for about a week. It 'felt' horrible. I put it back on. IMO, any cold-air kit will give you very minimal hp gains. Meaning that it's not something you can just strap on by itself and expect to beat your buddy in the cobra/mach who's been kicking your butt by 10 car lengths, but you'll notice the difference while driving. Especially high in the rpm range.. Also, if you have a Steeda Tower Strut Bar, the 'full length' won't fit.