Quite frankly, we were shocked at how exotic the 5-cylinder motor became after installing the AWE Cat Back exhaust system. This exhaust unlocks ~8hp at the crank, as well as giving the 2.5L engine a voice that turns heads. There is no interior drone at any RPM and sound volume (interior and exterior) is quite civilized - while still being noticable. The 2.5L Cat Back was designed with performance and longevity in mind, and features mandrel-bent 2.5 inch diameter tubing, thick .065" wall T304L stainless steel, double walled adjustable AWE exhaust tips to reduce heat discoloration, and performance verified on the AWE in house Mustang dyno.