Mercedes-AMG® GT XX Concept: A Record-Breaking EV Test Lab

When you look at the Mercedes-AMG® GT XX Concept, you will immediately notice its Sunset Beam Orange color, which is as bright as orange can get. Design-wise, it features a shark nose front, intricate hood venting, and a rounded four-door body that, aside from lacking a rear window, appears to be based on an existing Mercedes-Benz sedan. In other words, it appears to be a bold sedan, but familiar. However, this concept car is more about how it goes than how it looks, which is nothing short of revolutionary. Mercedes-Benz of Plano explains. 

The XX Concept is fully electric, but that’s just the beginning of the story. Beneath the bright orange paint is a tri-motor setup featuring a revolutionary axial flux electric motor design. It was created by British electric motor expert YASA – now a wholly owned subsidiary of Mercedes-Benz Group AG.   

Most electric motors in today’s EVs have a radial flux design, where the electromagnetic flux runs perpendicular to the axis of rotation. In contrast, the flux in an axial flux motor runs parallel to the axis. All the large components of an axial flux motor are slim discs, stacked with the stator placed between two rotors on each side. This setup allows for optimal power transfer from the stator to the rotors via the electric field. Practically, this means the motors are very powerful yet compact. In fact, they are about one-third the size of a conventional motor and roughly two-thirds lighter. For example, in the Concept AMG® GT XX, each of the two rear motors measures just 3.1 inches in width. Clearly, such a compact size opens new possibilities for drivetrain packaging. 

This wouldn’t mean much if they weren’t powerful. However, with one motor in the front and two in the rear, the total output on the Concept AMG® GT XX is 1,341 horsepower, and they can produce that power continuously without much concern for overheating.  

AMG® demonstrated this by taking the Concept AMG® GT XX to Italy’s renowned Nardo test track. They drove the car the equivalent distance of the Earth’s circumference, 24,901 miles, in just 7 days, 13 hours, 24 minutes, and 7 seconds, including charging stops. The car averaged 186 mph, which is well below its claimed top speed of 223 mph. 

The motors are powered by a similarly innovative battery. It uses NCMA (nickel/cobalt/manganese/aluminum) in the cathode and a silicon-rich anode. The cells are unusually tall and slim, which helps with heat dissipation under high load, thereby reducing cooling requirements. With an 800-volt architecture, the batteries can accept a charging speed of 850 kW at 1,000 amps, allowing for a gain of just under 250 miles in about five minutes, which is almost like a gas fill-up. Not many 850-kW chargers are available, but if this technology enters mainstream production cars, you might start seeing some.   

“The best minds in our global R&D network have contributed their extensive expertise – from Mercedes-Benz in Sindelfingen and Untertürkheim to Mercedes‑AMG®® in Affalterbach and YASA in the UK to our Formula 1 drivetrain experts at Mercedes‑AMG®® High Performance Powertrains in Brixworth. Together, they have developed the CONCEPT AMG®® GT XX and are providing an insight into pioneering drivetrain technology and the future of performance. The technology program pushes the boundaries even further and ventures into new ground. The CONCEPT AMG®® GT XX with its three axial flux motors now lifts performance and endurance to a completely new level.” – Markus Schäfer, Member of the Board of Management of Mercedes-Benz Group AG, Chief Technology Officer, Development & Procurement 

Additional innovative ideas are integrated into the concept vehicle. The door handles, among other components, are made from a man-made silk produced by genetically modified bacteria. It retains silk’s properties while being 100% biodegradable. The seat pads are 3D printed, which could enable extensive individual customization in production vehicles. The wheels feature movable elements that can sit flush to improve aerodynamics and then extend to enhance brake cooling, providing both an entrance and exit for air. The motion is activated by Bluetooth® from a central control unit.  

Some of these innovations might not be practical for production, but Mercedes-AMG® has plans for axial flush motors where just one 447-hp motor would provide enough power for most drivers. When the motors make their way to production cars in the Mercedes-Benz of Plano inventory, we will be sure to let you know.