Think of it as the opposite of the Ford Mustang GT's Quiet Start mode.
Exhaust note plays a big part in what we love about driving high-performance automobiles. Mercedes-AMG knows that at least as well as any other manufacturer in the business, and it's leaning into that with a feature called Emotion Start.
As Car and Driver reports, Emotion Start is a system that opens the flaps on the exhaust system and increases the revs when igniting the engine, allowing the engine to "come to life" upon starting up the engine – whether it's a 2.0-liter inline-four, a 3.0-liter V6, a 4.0-liter twin-turbo V8, or the dying breed that is the top 6.0-liter V12.
Every one of those engines that AMG builds – typically by hand by a single technician at its facility in Affalterbach, Germany – is turbocharged. The forced induction typically muffles the exhaust note, but the engineers at Daimler's performance division have gone to great lengths to ensure they sound like we expect a high-output engine to sound, whether it's installed in a ~$40k A35 sedan, a $75k GLC 63 sport-ute, or a $200k GT R Pro sports car. In 2021, the Silver Star automaker will finally begin delivering the thousand-plus-horsepower, $2.7-million Mercedes-AMG One hypercar, and we'd expect the system to feature there as well.
To activate Emotion Start, all you need to do is pull back on either one of the paddle shifters (which come standard on every AMG model) before pushing the start/stop button. If you want to keep the exhaust flaps open, you'll need to press the exhaust button on the center stack, which seems like a bit of unnecessary added effort. But then we suppose not everyone wants the exhaust burbling at full volume all the time. Leave it off and the smooth-revving German engine will stay on the down-low by default, sort of like the Quiet Start on the Mustang... but backwards.