The "V8 of the Electric Era": Mercedes-Benz Launches Serial Production of Revolutionary Axial Flux Motors in Berlin

In a milestone move for automotive engineering, Mercedes-Benz has officially inaugurated the large-scale serial production of its high-performance axial flux electric motors at the historic Berlin-Marienfelde plant. This development marks a paradigm shift in electric mobility, as the Stuttgart-based automaker transitions its oldest manufacturing facility into a state-of-the-art hub for cutting-edge EV powertrain technology. The new motors, characterized by their "pancake" design, are set to power the upcoming Mercedes-AMG GT 4-Door Coupé, signaling a new era of performance-oriented electrification.

The Technological Leap: Why Axial Flux?

To understand the magnitude of this shift, one must contrast the new technology with the status quo. For over a century, the internal combustion engine—specifically the V8—has been the gold standard for performance, offering high power density, instantaneous torque, and exceptional endurance. In the transition to electrification, traditional radial flux motors have served as the industry standard, but they face inherent limitations in size and thermal management.

The axial flux motor, derived from the innovative work of the British specialist Yasa (acquired by Mercedes-Benz in 2021), changes the fundamental physics of the electric drive. In a standard radial motor, the electromagnetic flux runs perpendicular to the shaft. In an axial flux motor, the flux runs parallel to the axis of rotation. This geometry allows the components—the stators and rotors—to be arranged in a sandwich-like, disc-shaped configuration.

The performance advantages are profound:

• Massive Power Density: Compared to conventional radial motors, the axial flux design requires less than one-third of the installation space and roughly one-third of the weight, while delivering up to three times the power output.
• Torque Characteristics: Because the magnetic field runs parallel to the shaft, the flux path is shorter, resulting in superior utilization of the magnetic field. This translates into unparalleled acceleration and vehicle handling.
• Thermal Management: Perhaps the most critical innovation is the cooling system. In radial motors, heat generated in the copper coils is notoriously difficult to dissipate, leading to performance "throttling" under high demand. The Yasa-designed motor utilizes a non-conductive fluid that flows directly over the copper coils. This enables sustained high-power output without the risk of thermal degradation.

Chronology: From Concept to Industrial Reality

The journey to the production line in Berlin-Marienfelde was not an overnight success but a carefully calculated evolution:

• 2021: Mercedes-Benz acquires Yasa, the UK-based pioneer of axial flux technology, signaling a long-term strategic commitment to proprietary, high-performance electric drive systems.
• 2023–2024: Intensive testing of the technology in extreme environments, including the "Concept AMG GT XX" prototype. During rigorous track testing in Nardò, Italy, the motor demonstrated its durability by running continuously under 35°C heat, completing over 40,000 km in seven days and setting 25 long-distance records.
• Mid-2026: Official inauguration of the production line at the Berlin-Marienfelde facility. Bundesverkehrsminister (Federal Minister of Transport) Patrick Schnieder attended the ceremony, underscoring the national importance of this industrial pivot.
• Present Day: Serial production commences, marking the debut of these units in the Mercedes-AMG GT 4-Door Coupé.

Data and Engineering Specifications

The specifications of the new "High Performance Electric Drive Units" (HP.EDU) are as impressive as the records they have broken. At the front axle, the motor measures just 9 cm in width, while the two motors at the rear axle measure roughly 8 cm each. These units are integrated into a compact housing along with a planetary gearbox, creating an exceptionally slim profile that allows for radical vehicle design possibilities.

The "Nardò Test" Proof-of-Concept

The capabilities of this technology were proven beyond doubt during the Nardò record runs. Over a seven-day period, the test vehicle performed at a constant 300 km/h, with charging stops utilizing an 850 kW power load. The fact that the motors showed zero performance degradation after 40,000 km of constant operation provides a clear answer to critics who argue that EVs cannot sustain high-performance output over long durations.

Industrial Implications: A New Era of Manufacturing

The transition to mass-producing axial flux motors presented engineers with a "blank sheet" scenario. The precision required for the disc-shaped geometry necessitated the development of 65 entirely new manufacturing processes, resulting in over 30 patent applications for the Berlin plant.

Precision Coil Winding

To maximize power density, Mercedes uses rectangular copper wire instead of traditional round wire. This allows for a higher "fill factor" within the stator. However, bending this wire into tight radii without damaging the insulation or thinning the cross-section is a feat of engineering. Mercedes implemented a bespoke robotic winding process that combines high-speed throughput with extreme structural integrity.

Laser Welding and Polymer Bonding

The connection of the coil ends within the restricted space of the stator is achieved through high-precision laser welding. This process ensures a minimal energy footprint, preventing the heat from damaging the delicate adjacent plastic components. Similarly, the use of AI-supported optical quality control ensures that every laser weld and polymer bond is verified in real-time.

The "Wedding" Process

The most complex phase, internally dubbed "The Wedding," involves the assembly of the stator between two rotor discs. The magnetic forces at play reach up to 9 kN (approximately 900 kg). To successfully marry these parts, the system must maintain a tolerance of less than 0.1 mm in the magnetic center. This is achieved through a dynamic control algorithm that uses high-frequency pulse corrections in the final 0.5 seconds of the assembly process—a level of manufacturing sophistication previously considered nearly impossible at scale.

Official Perspectives and Strategic Outlook

Michael Schiebe, former head of AMG and current Member of the Board of Management of Mercedes-Benz Group AG, emphasized the significance of this development: "Enormous performance and ultra-fast charging were consistently available, enabling these records. We have proven that our electric technology is not just an alternative, but a superior successor to the traditional internal combustion engines that have defined AMG for decades."

The shift at the Berlin-Marienfelde plant is not merely a product update; it is a cultural and structural transformation. By moving away from the production of legacy combustion components and toward high-tech electric motor manufacturing, Mercedes-Benz is securing the future of its German workforce. The facility is now positioned as the global competence center for Mercedes’ electric performance powertrains.

Future Implications for the Automotive Sector

The successful industrialization of the axial flux motor serves as a warning to the rest of the automotive industry. By proving that "Pancake" motors can be mass-produced with high reliability, Mercedes-Benz has effectively raised the bar for what an electric sports car can achieve.

1. Vehicle Dynamics: The slim design allows for lower centers of gravity and more flexible chassis configurations, potentially revolutionizing the handling characteristics of future luxury EVs.
2. Sustainability in Production: The move to local production of these highly efficient motors reduces reliance on external suppliers and streamlines the supply chain, while the high power-to-weight ratio contributes to better overall energy efficiency for the vehicle.
3. The New Benchmark: With the AMG GT 4-Door Coupé leading the charge, the industry is expected to see a race to replicate this technology. However, the complexity of the manufacturing processes—specifically the precision required for the "Wedding" of the rotors and stators—creates a significant technological barrier to entry for competitors.

As the automotive world watches, the Berlin-Marienfelde plant stands as a testament to German engineering’s ability to reinvent itself. The "V8 of the electric era" is no longer a concept—it is a reality, and it is ready to redefine the limits of electric performance.