Mercedes-Benz’s AMG performance car division has unveiled two new in-house developed petrol-electric plug-in hybrid (PHEV) drivetrains – the most powerful of which is set to provide future four-wheel drive AMG models with over 804bhp together with pure electric capability for zero-emission running over short distances.
The new PHEV drivetrains, part of what AMG calls its e-Performance strategy, are based on the German car maker’s existing twin-turbocharged 4.0-litre V8 and a newly developed longitudinally-mounted version of its turbocharged 2.0-litre four-cylinder petrol engine – the M177 and M139 as they are respectively codenamed, both mated to a nine-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.
The asynchronous unit, which provides a continuous 94bhp but has been developed to provide peak power of up to 201bhp along with 221lb ft of torque at a maximum 13,500rpm in more performance orientated driving modes, provides drive primarily to the rear wheels and, if necessary, to the front wheels for short periods via a carden shaft.
The new driveline architecture, originally hinted to 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, contributing to a more favourable 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 line-up despite an average 200kg increase in kerb weight model-for-model.
It also allows a higher combined torque rating as the electric motor operates independently to the nine-speed gearbox used by the combustion engine with its own two speed unit.
Electrical energy used to power the electric motor is stowed in a 400-volt 6.1kWh lithium-ion battery that uses cylindrical cells for compact packaging. 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 89kg.
The driver can choose between five different driving modes: Electric, Comfort, Sport, Sport+, Race and Individual.
AMG says the new gasoline-electric drivetrains are planned for several models in what it describes as “various expansion stages”.