Exhaust sound changes due to M button?
 

I purchased a White / Cinnamon X5 M a few days ago, and I was surprised to learn that the exhaust note varies with the use of the M button. It is a really nice feature. Does anyone know exactly what allows this to happen?

Thanks,
Dave

i have an e70 30i and i noticed the exhaust sounds different when i shift to Sport mode. i think the engine revs higher hence the change in sound.

Certainly, higher engine speeds= more sound, but I'm confident that there is a distinct difference from the moment that the M button is pressed. And the owner's manual mentions it, but does not elaborate.

There is a flap in the exhaust the opens up when the "M" button is pressed.

^^^what he said.

Exactly. See pic below.

Lets see pics of your White /Cinnamon combo. :thumbup:

Actually the sound change is not caused by the M button but by the settings of the M button (Sport).

Btw: could somebody check out if removing THIS hose actually causes the flap inside the exhaust tip to stay open permanently, hence providing the sportier sound all the time ?
If it works and you leave it removed, just make sure you put something inside that hose to avoid dirt/humidity entering.

I have read that its doable. Lets see who is the first here to try out.

Just a guess but... the flap may keep a little back pressure to help with lowerend torque. My guess would be that even without the M button pressed when the engine reaches hight RPM that it opens to allow the engine to breath and produce more hp.