[srbs73]

Originally Posted by BlownLSX

Refer to this thread. I have outlined all the information right from bmw.

Exhaust valve https://f44.bimmerpost.com/forums/sh....php?t=1738690

That information is incorrect for my G21 M340i at least. Changing the Engine Sound from Sporty to Reduced whilst the car is not in a Sport Driving mode, opens and closes the exhaust valve.

I just put the iPhone under the exhaust to be 100% sure (even though I could clearly hear it opening and the exhaust note changing). On the recording you can clearly see the valve activating.

Edit: Seen a few other posts that perhaps it is a different behaviour for the M340i. So maybe the same is true for the 128ti and M135i?