I know that aftermarket exhausts will be louder, i was more curious as to exactly how much louder. On my old 98 Impreza I had gone through many different exhausts, Borla, Custom, and even an Blitz Nur Spec R 3" race exhaust (gebus that thing was loud). The Borla was probably the best overall sounding of the 3 i put on it giving it a slightly louder sound without sounding ricer or being obnoxious.