2012 GT, V-8, 6MT- Stock Mufflers- Brembos

OK, I know I going to get some smart a.. replies but I'm serious with this Q.

With about 2500 miles on it, I've notice that when the engine is cold and warming up, the exhaust sound level going thru the gears is great but after it has warmed up, the noise level going thru the gears is substantially louder. Highway speeds in 6th is quiet.

Unlike my old Vette with the dual mode muffler, the M has almost straight pipes if it wasn't for the muffler. Those of you with an 11 or 12, does the 'going thru the gears' get progressively louder as the mileage goes up?

Jiggy One

Your explaination sounds correct. Going on 'cause and effect', it only gets louder when it's been driven, allowed to come up to temp, shut down for parking and on the restart and driving, the louder sound comes thru. That when the outside temps are in the 90's. Not blessed with cooler daytime temps as yet.

I've cked for leaks, including the H pipe but nothing found. and you don't get any of that distinct 'pipe loose, muffler leaking sound' when the car is shut down.

It's not that I mind the louder sound when going thru the gears, it's just that I would really prefer the quiter sound all the time. Highway at 60-70MPH in 6th is quiet . . . unless you step into it.