The “V8 of the Electric Era”: Mercedes-Benz Revolutionizes EV Production with Axial-Flux Technology

In a landmark shift for electric vehicle engineering, Mercedes-Benz has officially inaugurated the mass production of its advanced axial-flux electric motors at the historic Berlin-Marienfelde plant. This development marks a pivotal moment for the automotive industry, as the Stuttgart-based automaker transitions its oldest production site into a global center of excellence for high-performance electric drive units.

The commencement of production, attended by German Federal Minister of Transport Patrick Schnieder, signals more than just a new product launch; it represents a fundamental change in how high-performance electric vehicles will be powered, cooled, and manufactured in the future.

The Core Concept: Why Axial-Flux Changes the Game

For decades, the automotive world has been defined by the internal combustion engine, with the V8 configuration serving as the benchmark for power, torque delivery, and emotional response. Mercedes-Benz believes it has found the “V8 of the electric age” in the axial-flux motor.

Unlike the conventional radial-flux motors found in the vast majority of current EVs—where the magnetic field flows perpendicular to the axis of rotation—the axial-flux motor generates a magnetic field that runs parallel to the motor shaft. This design allows for a "pancake" geometry. Two rotors sandwich the stator, resulting in an incredibly compact, lightweight, and powerful unit.

Compared to radial-flux motors, the axial-flux design offers a staggering leap in performance metrics:

• Volume: Less than one-third of the space required.
• Weight: Approximately one-third of the weight of a conventional motor with similar output.
• Power Density: Up to three times the power-to-weight ratio.

These characteristics make the motor ideal for the high-performance requirements of the Mercedes-AMG division, debuting in the new AMG GT 4-Door Coupé.

A Chronology of Innovation: From Yasa Acquisition to Industrial Scale

The journey to the Berlin-Marienfelde production line began long before the recent ribbon-cutting ceremony.

• 2021: Mercedes-Benz acquires Yasa, a British specialist in axial-flux technology. This strategic move provided Mercedes with the intellectual property and engineering expertise necessary to take the "Pancake" motor from a prototype to a commercial powerhouse.
• 2022–2023: Intensive R&D phase focused on scaling the manufacturing process. The challenge was not just the physics of the motor, but the industrialization of processes that had never been performed at mass-market speeds.
• 2024: Validation phase via the Concept AMG GT XX. This test mule proved the durability of the technology, covering over 40,000 kilometers in seven days under extreme conditions at the Nardò test track in Italy.
• June 2026: Official start of mass production at Berlin-Marienfelde. The site, established in 1902, pivots from traditional engine assembly to becoming a high-tech hub for the future of electric mobility.

Engineering Breakthroughs: The "High-Performance" Data

The technical specifications of these motors are as impressive as their output. The motor is remarkably slim, measuring just 9 cm in width at the front axle and 8 cm at the rear. These units are integrated into what Mercedes calls "High Performance Electric Drive Units" (HP.EDU), which include a compact single-speed planetary gearset.

The Cooling Advantage

One of the primary limitations of traditional electric motors is thermal throttling. As copper windings heat up, resistance increases, and efficiency drops. The axial-flux motor utilizes a direct-cooling approach: a non-conductive fluid circulates directly over the copper coils. According to Yasa CEO Jörg Miska, this eliminates the "heat soak" common in radial motors. The result is sustained peak performance—a claim validated by the Nardò endurance records, where the test vehicles maintained 300 km/h for thousands of kilometers without degradation.

Performance Benchmarks

In the new AMG GT 4-Door Coupé, the system provides:

• 0–100 km/h acceleration: 2.1 seconds.
• Top Speed: 300 km/h (with Driver’s Package).
• Record-breaking consistency: During testing, the vehicle achieved 25 endurance records, including 10,000 km in 44 hours and an average daily distance of 5,300 km.

Manufacturing Complexity: The 98 Steps to Perfection

Mass-producing an axial-flux motor is an engineering feat that borders on the surgical. Mercedes-Benz reports that the manufacturing process involves 98 distinct steps, 65 of which are new to the company and 35 of which are entirely new to the global automotive industry. This technological leap has resulted in over 30 new patent applications.

The Stator Revolution

To maximize power density, Mercedes uses rectangular copper wire rather than traditional round wire. This allows for a higher "fill factor"—more copper in the same amount of space. Bending this wire into tight radii without damaging the insulation or changing the cross-section required the development of entirely new, high-speed automated bending machines.

The "Wedding" Process

The most challenging part of the assembly is the integration of the stator between the two rotor discs. Because these components are heavily magnetized, they exert attractive forces of up to 9 kN (approx. 900 kg). Keeping the stator perfectly centered within a tolerance of less than 0.1 mm during this "wedding" process is critical. Mercedes uses a sophisticated control algorithm that adjusts the positioning via high-frequency pulses in the final 0.5 seconds of the assembly, supported by ultra-sensitive sensors.

Laser and Polymer Precision

The assembly also relies on:

• Precision Laser Welding: To connect stator coil ends without damaging the surrounding plastic structures, the plant employs laser technology that minimizes energy input.
• AI-Controlled Polymer Welding: For sealing the housing, AI-based vision systems monitor the process in real-time. The system defines "virtual protection zones," ensuring that the laser only treats the intended surfaces, resulting in an oil-tight, highly durable seal.

Official Responses and Strategic Implications

"The axial-flux motor is the key to unlocking the next level of electric performance," stated Michael Schiebe, currently the Production Board Member of the Mercedes-Benz Group and former head of AMG. Reflecting on the Nardò records, he noted, "The ability to sustain enormous performance and facilitate ultra-fast charging under extreme temperatures proves that we have moved past the ‘limitation’ phase of electric mobility."

Market Implications

The transition of Berlin-Marienfelde serves as a blueprint for the industry. By successfully industrializing a technology once deemed "too complex for mass production," Mercedes-Benz has secured a competitive moat. Other manufacturers currently rely on radial-flux motors, which, while reliable and cheaper to build, lack the power-to-weight efficiency of the Yasa-designed axial-flux units.

This move effectively positions Mercedes-Benz to dominate the luxury EV performance segment, allowing them to offer the acceleration and power of a V8-powered supercar in a chassis that is lighter and more agile than ever before.

Looking Ahead

The investment in Berlin is not merely about the AMG GT. It signals a scalable future. As the technology matures and production costs decrease through these highly automated processes, we can expect to see axial-flux technology trickling down from top-tier performance models to the broader Mercedes-Benz EQ portfolio.

In conclusion, the launch of the axial-flux motor in Berlin is more than a production milestone; it is the manifestation of an engineering culture that refuses to compromise on performance, even in an era of electrification. By solving the most difficult manufacturing hurdles in modern automotive history, Mercedes-Benz has not only set a new standard for EVs—it has redefined the potential of the electric drivetrain for the decade to come.