New Mercedes-AMG C63 swaps V8 for 670bhp PHEV system

According to Wiebking, it’s not even essential that owners plug the car in. With many plug-in hybrids, once the battery is empty, they reduce the amount of electric power available and since it’s not efficient to recharge the battery using the engine, they usually don’t. The new C63 manages its energy differently.

Combining the strong electric motor, high-performance battery and direct cooling for the battery cells, the C63’s hybrid system can regenerate over 100kW of electric power under braking to feed back into the battery and give it the best chance of staying topped up. For extended hard driving, a 'boost mode' can also use the engine to ensure that the battery capacity never drops below 30%. 

Four-wheel drive

The C63 beats its rivals to adopting plug-in hybrid power, something that the Audi RS4 and BMW M3 aren’t expected to do for a few years. However, it is the last to offer four-wheel drive.

“The all-wheel drive system is one big plus for this car, because that was a pain point for our customers with the outgoing car”, said Wiebking, adding that a lot of owners felt the old rear-drive car was sometimes too much to handle. 

Unlike the C43, which has a fixed 31:69 torque split, the C63’s 4Matic+ is fully variable and can adjust the torque distribution depending on the drive mode and the circumstances. Like its big brother, the E63, it also has the ability to decouple the front axle in a dedicated drift mode.

Although the electric motor is mounted on the rear axle, it can also send power to the front when required. This means that even in EV mode, the C63 drives all four wheels.

The new C63 PHEV tips the scales at 2111kg. For comparison, the BMW M3 xDrive weighs 1780kg.

To keep that mass in check, AMG is throwing its entire arsenal of technology at the C63. At the front, the steering knuckles and supporting joints for the spring link are bespoke and lengthen the wheelbase by 10mm compared with the regular C-Class.

It still sits on steel coil springs, but uses a set of remote-reservoir dampers with a solid piston and external valves for bump and rebound. This improves damping performance under extreme conditions and results in both better control and more comfort. Unlike the racing dampers on which such a system is more commonly seen, the C63’s are electronically adjustable via the drive modes in three stages.

The C63 also gets four-wheel steering, allowing the rear wheels to turn up to 2.5deg in the opposite direction to the fronts (up to 62mph) or up to 0.7deg in the same direction at higher speed.

The C63 also gets upgraded brakes with six-piston calipers at the front (optionally gripping composite discs) and single-piston items at the rear. The friction brakes are supplemented by strong regenerative braking, adjustable through four stages.

Q&A: Jochen Hermann, chief technical officer, AMG

What was your aim with the new, hybrid C63?

"The way you drive this car, for us, is changing the game. The difference between the C63 V8 versus the new C63 S E-Performance is all about electrification. We are increasing performance while increasing the efficiency of our powertrain. I think that's very unique. This is what happened in Formula 1 and this is what we bring to the C-Class.

"And in order to do that, we took on board a lot of the software learnings that we got from the Formula 1 team, and especially from our Mercedes-AMG One project. And you know, since it took us a while to develop the AMG One, you can imagine there was quite a lot of learning. It's all about energy management. If you're not able to manage the energy in a P3 hybrid, then you might do one lap on the track and your battery would be empty. And that is why we put many more driving modes into the car. You have to make decisions, like Lewis Hamilton or George Russell would do."

The V8 is a defining feature of many AMGs. How do you sell customers on this new, very different car?

"In these times, it’s essential that we convince our customers and future customers of this new kind of technology, this new kind of game. I think an AMG always works best when you drive the car. The likelihood that you buy the car is always higher when you drive it than if you just look at it and read some specifications. We try to make it clear that we didn't just get rid of four cylinders. No, we added a lot more things. For example, the electric drive mode. Early in the morning, late at night, leaving your house fully electric - that's also something that people these days like. We have some very easy ones that can bring people to this car. For example, people said they missed all-wheel drive in their C63. Now they can have it."