A lot of the new weight would be concentrated in the rear, preserving weight distribution

cooling circuit with 14L of its own fluid. AMG claims the battery applies learnings direct from its F1 operations and is made for racetrack performance, saying it has twice the power density of a conventional battery.

Wheels understands the hybrid C63 will offer plug-in recharging ability, and AMG did confirm an electric-only mode available up to 130km/h. EV range was not revealed, with AMG simply saying that, unlike other performance hybrid systems, its system is built for additional power and overall efficiency rather than maximum electric-only range.

“Our concept is new and focused on getting performance into a hybrid powertrain,” said head of electric powertrains Jochen Schmitz to Wheels in a video Q&A.

“[We wanted to prioritise] racetrack usage and stuff like that into this hybrid system. Many of the well-known parallel P2 hybrids aren’t focused on performance; they’re more focused on range or other stuff, so it was on us to go this new way completely on our own.”

The 150kW electric motor, which spins to 13,500rpm, feeds a two-speed rear-mounted gearbox, with second gear engaging from 140km/h.

A nine-speed MCT (wet clutch) paddle-shift automatic transmission continues to be employed, slung off the back of the four-cylinder engine. And for the first time the C63 will utilise brake-by-wire, with only a digital connection between the pedal and the brakes themselves.

Four stages of brake recuperation will be available, with the highest setting scavenging up to 90kW and providing a proper one-pedal driving feel.

The C63 will offer six driving modes. Electric; a heavily hybridised Comfort with silent electric start; Sport for general performance; Sport Plus and Race (featuring ‘always on’ electric motor boost); and a customisable Individual mode.

While there is no word yet on overall vehicle weight, engineers said all the components of the new hybrid system weigh about 200kg, with the battery itself being 89kg. The M139 engine weighs about 50kg less than the outgoing M177 4.0-litre twin-turbo V8.

The all-wheel-drive system will also add kilos, although further weight savings could be possible through increased use of aluminium in the new 206-series C-Class body. The current twin-turbo rear-drive four-door C63 S weighs 1730kg, so we estimate the new W206 C63 S sedan would come in around 1950kg. One positive is that a lot of the new weight would be concentrated in the rear, preserving weight distribution.

For C63, AMG is expected to work carefully on the M139’s sound as well. “Will it sound like a V8? No, of course it will sound like a very high-performance drivetrain,” said engine specialist Hannes Lohrmann.

AMG has not yet stated fuel figures for its hybridised models but has promised “outstanding efficiency”.