After doing much research on this and other forums, including listening to sound clips, I have narrowed the choice down to these 2 finalists. My criteria are: deep sound, no raspiness, not overbearing on a 2 hour drive and high quality SS. While I am not expecting any real HP gain, I do not want to lose any either. The Hymee website posts a dyno chart that shows a slight gain, but I can not seem to find any performance data at all on the AutoExe exhaust. Also, I noticed some of the other aftermarket exhausts use 3 inch OD piping while the AutoExe uses 2.4 inch (60.5mm) piping and the Hymee uses 2.5 inch piping. Don't know if I should be concerned about that or not. Anyone have any experience or performance data for the AutoExe exhaust?

Also, my car is a 2005, 2 wks. old with less than 100 miles on it. Is there any benefit to waiting until the engine is broken in before changing out the exhaust?

Any input would be greatly appreciated.

Safe motoring.

 

I have stayed with autoexe tiatanium catback for months. My car is a 2004 AT one. The other tune about engine is Mazdaspeed drop-in filter and Odula intake pipe.
Compared with the factory pipe, the sound level was almost the same but deeper in tune. It roars lounder at higher rev range.
This catbacke adds some boost in low rev range(below 3000rpm). I did not dyno it so I can't tell you how much gain it brought; but I stay with 3rd gear longer druing driving on hills.