Mercedes-AMG Turns to PHEVs in New e-Performance Push

Mercedes-Benz’s AMG performance car division unveils two new, in-house-developed gasoline-electric plug-in hybrid drivetrains – the most powerful of which is set to provide future all-wheel-drive AMG models with more than 804 hp together along with pure electric capability for zero-emission operation over short distances.

The new PHEV drivetrains, part of what AMG calls its e-Performance strategy, are based on the German automaker’s existing twin-turbocharged 4.0L V-8 and a newly developed, longitudinally mounted version of its turbocharged 2.0L gasoline 4-cyl. – the M177 and M139 as they are respectively codenamed. Both are mated to a 9-speed AMG torque-converter-equipped MCT-Speedshift gearbox.

In an electrification process aimed at increasing their reserves while providing added efficiency for lower average CO2 emissions, the AMG combustion engines are combined with an electric motor integrated into the rear axle assembly (below, left).

The asynchronous unit, which provides a continuous 94 hp but has been developed to provide peak power of up to 201 hp at a maximum 13,500 rpm in more performance-oriented driving modes, provides drive to the rear wheels but can be transferred to the front wheels via a cardan shaft.

The new driveline architecture, originally hinted at on the Mercedes-AMG GT concept car revealed at the Geneva motor show in 2017, departs from the arrangement used by standard Mercedes-Benz PHEV models, which employ an electric motor integrated in the front of the gearbox housing.

The result is a more favorable front-to-rear weight distribution that AMG says is crucial to its future e-Performance models retaining the handling properties of its existing combustion engine lineup despite an average 440-lb. (200-kg) increase in curb weight model-for-model.

It also allows a high combined torque rating, as the electric motor operates independently of the 9-speed gearbox used by the combustion engine via its own 2-speed unit and limited-slip differential – all integrated into the rear axle.

Powering the electric motor is a 400V, 6.1-kWh lithium-ion battery that uses 560 cylindrical cells stacked horizontally. Developed in partnership with British-based High Performance Powertrains – the Mercedes-AMG-owned company responsible for much of the engineering of the company’s F1 race car drivetrains – it is claimed to weigh 196 lbs. (89 kg).

AMG says the new gasoline-electric drivetrains are planned for several models in what it describes as “various expansion stages.”

The V-8-based PHEV powerplant, which will first appear in the GT73e 4Matic 4-door going on sale in North America later this year, is claimed to develop more than 804 hp and more than 738 lb.-ft. (1,000 Nm) of torque – sufficient, according to preliminary data released by AMG, to provide the Porsche Panamera SE-Hybrid-rivaling sedan with 0-62 mph (100 km/h) acceleration in 3.0 seconds.

Further models set to receive the V-8 PHEV unit include the still-unconfirmed S73e 4Matic and SL73e 4Matic.

Mercedes-AMG Performance Hybrid-Electric Drive unit

The 4-cyl. PHEV drivetrain will debut on the successor to the C63 4Matic as the C63e 4Matic in early 2022. Its combustion engine adopts a new electric turbocharger to develop up to 443 hp and 442 lb.-ft. (599 Nm) of torque. In combination with the same electric motor and battery used by its V-8 PHEV sibling, it is claimed to offer more than 643 hp and 516 lb.-ft. (700 Nm) of torque.

The driver can choose between five different driving modes: Electric, Comfort, Sport, Sport+, Race and Individual.

AMG is yet to reveal the electric range of its new PHEV drivetrains. But while emphasizing the focus is more on performance than zero-emission distance capability, it does suggest short distances will be possible on the power of the electric motor and battery alone.

The new AMG drivetrains recover kinetic energy on the overrun and under braking in four stages: Level 0, 1, 2 and 3 – selectable by the driver via the right-hand-side steering wheel button. In Level 3, the generator can capture up to 90kW of electrical energy, according to AMG.

The battery can be charged at a maximum 3.7kW. The socket port is integrated into the right-hand side of the rear bumper on the GT73e 4Matic 4-door.

Mercedes-AMG GT73 4Matic 4-Door-rear 0.75