The gradual electrification of the Mercedes-AMG brand continues with the most powerful S-Class. The engine in the Mercedes-AMG S63 E Performance PHEV will be familiar to any AMG fan, though: it’s a 4.0-liter twin-turbocharged V8 producing 603 hp and 664 lb-ft of torque on its own. That torque figure is on tap between 2,500 and 4,500 rpm.
Those outputs match the old S63, but the ace up the new car’s sleeve is its rear permanently excited synchronous electric motor, which adds another 188 hp and 236 lb-ft. Combined, the outputs are a spectacular 791 hp and 1,055 lb-ft.
With the variable AMG Performance 4Matic+ all-wheel-drive system sending power to all four wheels and continuously varying the front/rear torque split, the S63 E Performance can complete the 0-60 mph sprint in a mere 3.2 seconds before reaching a limited top speed of 180 mph. Although that’s just a few tenths quicker than the old S63, any gains at this level are to be admired.
The V8 is hooked up to the AMG Speedshift MCT 9G transmission, which is an automatic with a wet multi-disc start-off clutch. Like the Porsche Taycan, the rear-mounted electric motor uses a two-speed transmission that helps deliver both agile starts and continuous performance at high speeds. An electric actuator will automatically engage second gear at around 87 mph.
Optimized for performance rather than range, the high-performance 13.1-kWh battery – which features direct cooling of the battery cells – can deliver 94 hp of continuous mechanical power and 188 hp of peak mechanical power, although the latter is only for ten-second intervals.