I'm new to this as well. Just picked up my 2016 M4 less than two weeks ago and haven't had the chance to read about all the settings. I do notice that my car starts in Efficient mode for the engine setting. It's pretty quiet when driving. When I switch it to Sport, the exhaust is much louder/throatier. Not sure if that's what you're experiencing but that's what this newbie here has noticed.
