on an otherwise stock 02 GT. It's my first aftermarket exhaust part ever so I can't really compare it against anything. Supposedly these are louder outside, quiter inside, and flow alot better... but how would I know. The interior drone is pretty loud with the windows up, but not TERRIBLE. With the windows down I can barely hear them, but I imagine they sound louder from the outside, they better! I don't mind the drone as long as people outside can hear it too. Have only driven it a few blocks bc I had some stuff to do but so far I'm liking them.