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

In a monumental shift for automotive engineering, Mercedes-Benz has officially inaugurated the large-scale serial production of its groundbreaking axial-flux electric motors at the historic Berlin-Marienfelde plant. This development marks more than just a change in drivetrain technology; it signals a total transformation of the century-old Berlin site into a global high-tech hub for electric powertrain manufacturing. With the arrival of Federal Transport Minister Patrick Schnieder for the official ribbon-cutting ceremony, the message was clear: German automotive manufacturing is pivoting toward a future defined by radical efficiency and extreme power density.

The Technological Leap: Why Axial-Flux?

For decades, the internal combustion engine—specifically the V8—has been the gold standard for high-performance vehicles, offering immediate torque and high rev-ranges. In the transition to electrification, the industry has relied heavily on radial-flux motors, which, while reliable, often come with significant weight and space trade-offs.

Mercedes-Benz now positions the axial-flux motor as the "V8 of the electric age." Unlike conventional radial motors, where the electromagnetic flux runs perpendicular to the rotor’s axis, the axial-flux design channels the magnetic flux parallel to the rotation axis. This allows for a "pancake" architecture, where two rotors sandwich a central stator.

The physical implications are staggering. By adopting this configuration, Mercedes-Benz has achieved:

• A reduction in size: The motor occupies less than one-third of the space required by traditional units.
• A reduction in weight: The weight is similarly slashed by two-thirds.
• Triple the performance: The power output relative to volume is three times higher than that of standard electric motors.

Chronology of a Revolution: From Yasa to Serial Production

The journey of this technology is one of rapid acquisition and intense R&D. The roots of the current production engine lie in the innovations of Yasa, a British electric motor specialist that caught the eye of the Stuttgart-based automaker.

• 2021: Mercedes-Benz AG acquires Yasa as a wholly-owned subsidiary, signaling its intent to lead in high-performance electric propulsion.
• 2023–2024: The automaker utilizes the "Concept AMG GT XX" as a rolling laboratory. During grueling tests in Nardò, Italy, the powertrain demonstrates unprecedented endurance, covering 40,000 km in under eight days under extreme heat.
• 2026 (Present): The Berlin-Marienfelde plant, founded in 1902 and once synonymous with combustion engine components, completes its transformation to mass-produce the axial-flux unit for the new Mercedes-AMG GT 4-Door Coupé.

Performance Metrics and Real-World Dominance

The performance figures are not merely academic. In the new Mercedes-AMG GT 4-Door Coupé, the technology enables a 0–100 km/h sprint in just 2.1 seconds, with a top speed of 300 km/h. However, the true genius lies in the "High Performance Electric Drive Units" (HP.EDU).

At the front axle, the motor measures less than 9 cm in width, while the dual-motor setup at the rear occupies only 8 cm per unit. These motors are paired with compact, single-stage planetary gearsets. This modularity allows the vehicle to maintain high-speed performance without the heat soak that plagues standard EVs.

During the Nardò endurance trials, the technology showcased its superiority. Even at ambient temperatures of 35°C, the car maintained a constant 300 km/h, proving that the "Pancake" motor does not suffer from the performance degradation typically associated with overheating copper windings.

The Secret Sauce: Advanced Cooling and Material Science

The key to this endurance is a proprietary cooling technique. Instead of cooling the motor housing, a non-conductive fluid directly bathes the copper coils. Jörg Miska, CEO of Yasa, explains the limitation of the status quo: "In a classic radial drive, the copper coils develop heat that is notoriously difficult to dissipate. Once the copper hits a certain temperature threshold, power output drops—the energy essentially evaporates."

By cooling the source of the heat directly, Mercedes-Benz has unlocked a higher continuous power rating, making the motor ideal for the rigorous demands of the AMG performance brand.

Manufacturing: A New Industrial Paradigm

Perhaps the most significant achievement is not the motor itself, but the industrial process required to build it at scale. Mercedes-Benz has implemented 98 distinct process steps, 65 of which are entirely new to the company, and 35 of which are globally unique. This has resulted in over 30 new patents.

The Challenge of the Copper Coil

To maximize power density, the stator uses rectangular copper wire instead of traditional round wire. This allows for a higher "fill factor"—more copper in the same amount of space. However, bending rectangular wire into tight radii without damaging the insulation or thinning the cross-section is a feat of engineering. Mercedes developed a bespoke high-speed bending process that maintains precision at industrial cycle times.

Precision Laser Connectivity

Connecting these coils is equally complex. Given the tight space, traditional soldering is impossible. The solution is a high-precision laser welding process that connects the coil ends with minimal heat input, preventing damage to the surrounding plastic structures.

The "Wedding" Process

The final assembly, dubbed the "Wedding" (a traditional German manufacturing term for the joining of major components), is arguably the most impressive phase. As the stator is inserted between the two magnetic rotors, it is subjected to massive magnetic forces of up to 9 kN—the equivalent of 900 kg of pull.

To maintain a tolerance of less than 0.1 mm, the production line uses sophisticated AI-driven algorithms. These systems provide high-frequency corrective impulses in the final 0.5 seconds of the assembly, ensuring the stator remains perfectly centered in the magnetic field.

Official Responses and Strategic Implications

Michael Schiebe, former head of AMG and current Production Board Member of the Mercedes-Benz Group, highlighted the success of the technology during the Nardò trials. "Enormous performance and ultra-fast charging were available continuously, which enabled these records," he stated. He emphasized that the ability to handle 850 kW of charging power while maintaining such high thermal stability is a game-changer for the entire electric ecosystem.

The implications for the wider automotive market are profound. By establishing a dedicated center for high-performance electric motors in Berlin, Mercedes-Benz is insulating itself against the volatility of the global supply chain while setting a new benchmark for what is possible in EV architecture.

The Future: A New Benchmark for Industry

The transition of the Marienfelde plant is a blueprint for how legacy automotive sites can survive the transition to electrification. By investing in highly automated, AI-assisted, and patent-protected manufacturing, Mercedes-Benz has not only secured the future of the Berlin site but has also redefined the competitive landscape of the performance electric vehicle market.

As the industry watches, the "V8 of the electric age" is no longer a concept or a prototype. It is a mass-produced reality, rolling off the lines in Berlin and heading for the world’s most demanding race tracks and roads. The message to competitors is clear: the era of the axial-flux motor has arrived, and it is here to stay.