Power comes from the now-familiar 4.0-liter biturbo V8, but what makes the S63 so incredible is the almost nonchalant manner for which it dishes up performance. It’s as heavy as a big SUV, but being a sedan it handles that weight with much greater poise. It’s quiet and comfortable, filled with tech, and as our personal experience confirms, having a conversation with passengers while doing 164 mph on the Autobahn is pretty much a non-event.