You will feel a little (+2-5 Hp) performance change if you install the K&N's and you will realize a 1-3 mpg increase in gas mileage; but the best thing I felt after changing was that the SOUND of the engine changed under full throttle. It gave a subtle Euro Roar that was really cool. I had a '76 TR-6+ Triumph with the inline 6 that had almost the same sound, under power, when I owned it back in the early '80's. That was a fun car with a Jaguar front end that could probably keep up with many of the medium-faster cars today. And it was Screaming Blaze Yellow. Fun car...I miss it. Fade to black and lights up on stage one...The Crossfire I have today kicks A## over most of the previous cars I have owned. It has a drivability and just plain fun response to driving inputs that is so cool. I want to try Autocross with it and I'm slowly gathering data on that sport...