New 2024 Mercedes-AMG E63 swaps V8 for straight-six PHEV

The next Mercedes-AMG E63 is set to swap its V8 petrol engine for an advanced new straight-six plug-in hybrid drivetrain, providing it with greater power and the capacity for electric-only driving.

Set to be unveiled in 2024, the hot saloon/estate will be the first in a series of Mercedes-AMG models to adopt the new electrified drivetrain, which uses a similar ‘P3’ hybrid arrangement to the recently launched Mercedes-AMG GT 63 S E Performance 4-Door Coupé and Mercedes-AMG C63 S E Performance.

Official details remain under wraps, but Autocar can confirm the hottest version of the next Mercedes-Benz E-Class will receive a heavily reworked version of Mercedes' M256 turbocharged 3.0-litre straight-six petrol engine, mounted longitudinally and working in tandem with an electric motor on the rear axle.

The extent of the modifications made to the M256 by AMG remains unclear. However, it appears set to share a number of key components with the M139L and M177 engines used by the C63 and GT 63, with a similar in-line design and internal dimensions, including an 83mm bore measurement and 90mm bore centre spacing.

The asynchronous motor set to feature in the new E63 is also similar in construction and performance to the 201bhp unit used by the other electrified '63’ models, according to insiders at Affalterbach.

Electrical energy is stored in a 4.8kWh (usable) 400V lithium ion battery mounted under the boot floor.

AMG is claimed to be targeting an output of more than 700bhp and 884lb ft for the new drivetrain. For context, the four-cylinder system in the C63 delivers 671bhp and 752lb ft of torque, while the V8 system in the GT 63 kicks out 831bhp and 1031lb ft.

By comparison, the M177 twin-turbocharged 4.0-litre V8 petrol engine that powers the existing E63 S develops 604bhp and 626lb ft of torque.

The secret to the significant increase in power and torque with the new plug-in hybrid systems is the fact that the output isn't limited by the gearbox, because the reserves from the motor are sent directly to the rear wheels via a two-speed gearbox and an electronically controlled limited-slip differential.