The Mercedes-AMG S63 has been reborn as a plug-in hybrid (PHEV) performance saloon developing up to 791bhp.
Set for UK sale early next year, the advanced saloon runs an updated version of the twin-turbocharged 4.0-litre V8 petrol engine used by its predecessor but also adopts a rear-axle-mounted asynchronous electric motor and a 13.1kWh lithium-ion battery – a set-up similar to that of the recently introduced Mercedes-AMG GT 63 S E Performance 4-Door Coupé.
The new petrol-electric drivetrain brings an additional 214bhp over the old S63 4Matic, making the 2023 model, officially called the S63 E Performance, the most powerful series-production S-Class model to date.
Even more impressive is the increase in torque. It extends by 391lb ft to 1054lb ft. Up to now, the most powerful S-Class was the previous-generation S65, whose twin-turbocharged 6.0-litre V12 petrol engine delivered 624bhp and 737lb ft.
The added reserves aren't without a substantial weight penalty, though. With a claimed kerb weight of 2595kg, the new S63 tips the scales a considerable 525kg above its predecessor, albeit with what Mercedes-AMG’s head of technical development, Jochen Hermann, describes as “optimised weight distribution”.
Drive is channeled through a nine-speed AMG Speedshift MCT automatic gearbox (for the ICE) and two-speed gearbox (for the motor) as well as a fully variable AMG Performance 4Matic+ four-wheel drive with torque-vectoring for the rear wheels.
This gives the flagship AMG saloon an official 0-62mph time of 3.3sec and a governed top speed of 155mph as standard or 180mph in combination with an optional AMG Driver’s Package.
Altogether, there are seven driving modes: Electric, Comfort, Battery Hold, Sport, Sport+, Slippery and Individual.
The combination of a motor and a battery gives the S63 the capability to travel short distances on electric power alone. In Electric mode, it delivers up to 188bhp and 236lb ft of torque along with official WLTP economy of 2.90 miles per kWh and a claimed electric-only range of 20.5 miles.