AMG’s New C63 Is a 671-HP PHEV

Pour one out for the charismatic V-8 engines that have made the Mercedes-AMG C63 such a rowdy sports sedan. They will be missed. Now make way for the 2024 C63 S E-Performance, which goes on sale next year sporting an elaborate four-cylinder plug-in-hybrid system good for a combined 671 horsepower. Traditionalists may not be happy, but short of stealing one of the company’s AMG One hypercars, this is as close as mere mortals are likely to get to experiencing a Formula 1–inspired powertrain on the street.

Pop the C63’s hood, and the source of the car’s fire and brimstone is revealed to be a longitudinally mounted 2.0-liter turbo four that produces an absurd 234.5 horsepower per liter—469 in total, or the same as the outgoing C63’s twin-turbo 4.0-liter V-8 made in standard tune. That power comes with no discernible lag, thanks to an electric motor on the shaft connecting the turbocharger’s compressor and turbine wheels. Powered by a 400-volt electrical architecture, which also runs a belt-driven starter-generator, the motor helps spin the turbo to 150,000 rpm almost instantly, generating up to an insane 37.7 psi of boost. While the loss of the previous model’s thunderous V-8 acoustics is indeed sad, the raspy thrum of this new M139l four-banger does sound fierce at its 6750-rpm power peak, even when you choose to amplify it through the speakers inside and outside the car.

The grunt from this hand-assembled four routes to AMG’s nine-speed automatic transmission with a clutch pack in place of a torque converter. From there, it’s on to the newly added variable 4Matic+ all-wheel-drive system with a tire-smoking Drift setting that locks out the front axle. The C63’s hybrid drive unit—a beefy electric motor with its own two-speed gearbox, plus an electronically controlled limited-slip differential—is situated on the rear axle and can power all four wheels in EV mode. Atop it sits a 196-pound lithium-ion battery with 4.8 kWh of usable capacity, which shrinks this C-class’s trunk volume from 13 cubic feet to 10.

Quick power delivery is the hybrid system’s strategy: The drive unit is rated for a continuous 94 horsepower or a jolt of 201 horses for 10 seconds when you mat the accelerator past its kick-down detent. EV range is only eight miles in the optimistic European cycle, though the C63 accelerates well solely on electrons up to 81 mph. A 3.7-kW onboard AC charger can replenish the battery in about two hours via a 220-volt outlet.

In normal driving, the new C63 is far tamer than the rear-drive-only model it replaces. It hums along quietly on electricity or to a muffled four-cylinder beat, its revised coil-spring suspension soaking up many of the bumps that previously would have jarred its occupants’ spines. Standard rear-wheel steering that turns up to 2.5 degrees aids both low-speed maneuverability and high-speed composure, while a front track that’s 3.1 inches wider than lesser C-classes helps plant it during big directional changes. The pedal controlling the six-piston front and single-piston rear brakes (carbon-ceramic front rotors will be available after launch) has the firm, positive feel that’s lacking from the C300 model’s mushy stoppers. Overall, the C63 is 3.6 inches longer than the standard car and rides on a wheelbase 0.4 inch longer. A few E-Performance badges and a subtle hood vent are its key tells. Inside, you’ll find deeply bolstered AMG sport seats, plus performance and hybrid system readouts in the 12.3-inch digital gauge cluster and the 11.9-inch center touchscreen

No fewer than eight drive modes manipulate the C63’s engine and drivetrain, three-position adaptive dampers, steering sensitivity, and stability control via two control pods on the steering wheel. Though the kick-down boost is always available, the rear drive unit otherwise contributes 25 percent of its potential in Comfort mode, 65 percent in Sport, and 80 percent in Sport+ and Race. There are also Individual, Slippery, and Electric modes, plus a Battery Hold setting that runs the gas engine more to maintain a desired state of charge. Tapping the right steering-wheel pod calls up four levels of regenerative braking, from zero to near one-pedal operation.

Unleashed on the mountain roads of southern Spain, the C63’s obsessive engineering starts to make sense. Its improved front-to-rear weight distribution, combined with the rear-axle steering and a nicely weighted helm, helps it attack corners with solid poise and sharper reflexes. Bury the right pedal and it rockets out of corners with up to 752 pound-feet of combined torque. Paddles on the steering wheel provide manual control of the nine-speed transmission, but it never missed a beat when we let it do its thing in Drive. Similarly, shifts from the two-speed rear end at around 87 mph are all but imperceptible.

As with AMG Petronas’s Formula 1 race cars, the C63’s challenge lies in reliably extracting the most speed from its electrical system. While it can recuperate an impressive amount of energy under braking, repeatedly deploying its electrons requires a keen eye on the battery’s limited charge. Channel your inner Lewis Hamilton. The Race mode’s Boost program helps in this regard, coaching the driver on when to light the afterburners based on how aggressively you plan to lap one of 30 currently mapped circuits. Around the flowing tarmac of the Ascari Race Resort, for example, its Endurance setting (there’s also a Qualifying mode) called for full thrust down the track’s two back straights, which left ample time to harvest energy and cool the battery in between.

Yet even with a considerably quicker 60-mph estimate of three seconds, the new C63 can’t escape the physics of carrying around what are essentially two distinct powertrains. The new hardware has added some 700 pounds of mass (we estimate it at 4700 pounds overall), which you can feel in faster corners and in braking zones, taxing the grip of its somewhat narrow 19- or 20-inch Michelin Pilot Sport 4S summer tires (265-series width in front, 275s in back). We didn’t get to drive on the optional Michelin Cup 2 R tires, but we’d probably want them for track days.

An estimated base price now approaching $100,000 reflects the C63’s status as an engineering marvel with a greater bandwidth of capability. Its high-tech rebirth also reinforces that, with the help of powerful electric motors, wild internal-combustion engines need not die out just yet. We still have a soft spot for its brutish V-8 predecessors. But the C63 S E-Performance leaves little doubt: The future of AMG performance looks to be as exciting as it is complicated.