SANTA MONICA, Calif. — Although it’s best known as an opulent halo car that features Mercedes-Benz’s latest innovations, the S-Class tends to take on a slightly different sense of purpose after the engineers at Affalterbach get their hands on it. AMG-tuned versions of the full-sized sedan date back as far as the early 1970s with the W116 generation, and the formula has stayed admirably consistent throughout the decades: Stuff a massive power plant in the engine bay and support it with specialized performance hardware for maximum effect. That tradition continues with the new S 63 E Performance, but how that capability is achieved changes in some significant ways.
As the de facto successor to the dearly departed, V12-powered S 65, the S 63 E Performance seeks to further prove there is a replacement for displacement by pairing a boosted V8 with an AMG-developed hybrid system. Together, the powertrain develops a peak 791 horsepower and 1,055 pound-feet of torque, figures which make this the most powerful sedan in Mercedes-AMG’s history. It also allows the S 63 E Performance to be motivated purely by electricity for approximately 20 miles on a charge (its 13.1-kilowatt-hour battery
While this approach addresses the concerns of enthusiasts and regulators, it results in a powertrain that’s stunningly complex and a car that tips the scales at over 5,800 pounds – or about 900 pounds more than its predecessor. That’s not a negligible amount of mass, but the S 63 E Performance is also packing some clever engineering to address it.
Before diving into the mechanical nitty-gritty, let’s take a moment to soak in the S 63 E Performance’s aesthetic. It’s not a wild departure from a standard S-Class, but elements like the AMG-specific grille, front fascia, side skirts, rear diffuser and quad-tipped exhaust deliver a sportier appearance while keeping things relatively low-key. It’s a similar story inside, where aside from the flat-bottomed AMG steering wheel, badging and S 63-specific trim elements, it’s largely business as usual. That also means there’s still a distinct emphasis on providing a luxurious experience to the passengers in the back seats, as S-Class owners are far more likely to be chauffeured around in their cars than those who are cross-shopping E 63s and M5s.
Up front, the 12.8-inch OLED touchscreen infotainment system offers up real-time information about the hybrid system’s state of charge, electric motor temperature and battery temperature, along with readouts that provide a visual representation of the power flow of the entire drive system. The digital gauge cluster and head-up display can be customized with AMG-specific layouts for a more sport-oriented look, too.
The big news, though, is that powertrain. There’s a lot going on here, so we’ll start with the internal combustion stuff. Under the hood is AMG’s familiar 4.0-liter, twin-turbocharged V8 that develops 603 horsepower on its own, and it’s matched up with a nine-speed automatic gearbox that sends power to all four wheels through a variable all-wheel-drive system.
Situated behind the transmission is a permanently excited synchronous electric motor that offers 188 horsepower for up to 10 seconds at a time, or 94 hp continuously. It also generates 236 lb-ft of torque — all that power allows the S 63 E Performance to operate at speeds of up to 87 mph purely on electricity. The hybrid system has its own two-speed transmission as well as an electronically controlled limited-slip differential. The electric motor can control drive torque to each wheel independently through the limited-slip differential, effectively creating a supplemental, hybrid-system-based electronic stability control system. According to Mercedes