The tuner offers the 850 pack which is called that based on the horsepower the car makes after the modifications.
The Brabus 850 is a very obnoxious car: it’s big and noticeably luxurious, like any S-Class, but it’s hugely fast, sprinting to 100 km/h or 62 mph in a bit over 4 seconds, and it’s extremely loud; too loud, even, for what it is. We wonder if an exhaust like that is really legal all around the world – it probably isn’t and is the kind of noise that sets off alarms as its passes by at full bore.
The noise it makes is obviously very pleasurable to the ear, but it sounds close to what a V8 racing car would sound like. That’s fine on a track but I don’t think pedestrians will go “hey, what a cool modified S-Class;” they’d probably be very cross if this V8 racket would ruin their quiet cup of coffee or leisurely stroll, which probably happened during the shooting of this video, as it’s set in Monaco where the sidewalks are packed.