Mercedes begins mass production of axial flux motor that promises to revolutionize electric vehicles

What happened?

On June 9, Mercedes-Benz announced the start of series production of its axial flux motor at the Berlin-Marienfelde plant, founded in 1902 and now converted into a center of excellence for high-performance electric motors. The factory, with 30,000 square meters, three halls, and seven production lines, represents a significant investment in the brand's electrification. The first model to equip it is the Mercedes-AMG GT 4-Door Coupé, a vehicle that, despite being overshadowed by the debut of the Ferrari Luce, marks a technological milestone. This announcement is not an isolated event: it is part of a broader Mercedes strategy to electrify its high-performance range, competing directly with manufacturers like Tesla, Porsche, and Rimac. The Marienfelde plant, which originally produced combustion engines, has been completely transformed to house electric motor production, a process that required years of planning and an investment of several hundred million euros. According to Mercedes data, the plant has the capacity to produce tens of thousands of motors per year, although the exact figure has not been disclosed. This move also has labor implications: the company has retrained many of its workers, training them in new skills for manufacturing electrical components, in a context where the German automotive industry faces a transition to electric mobility.

Why is this motor different?

Most current electric cars use radial flux motors, where the magnetic field goes from the center outward. In the axial flux motor, the field runs parallel to the axis of rotation, allowing the internal components to be stacked like layers of a sandwich. This makes it much more compact and lighter for the power it generates. While a typical radial motor offers about 4-5 kW/kg, Mercedes' axial motor reaches up to 14 kW/kg, according to data from YASA, the British company acquired by Mercedes in 2021. In practical terms, this means the motor can produce up to 480 kW (644 hp) in a package weighing only 24 kg, comparable to a carry-on suitcase. Additionally, its design allows it to be integrated directly into the transmission or wheels, reducing drivetrain complexity. Efficiency is also superior: while a typical radial motor has a maximum efficiency of 90-95%, the axial motor can exceed 97% under optimal conditions, according to studies from the University of Oxford. This translates into greater vehicle range, as less energy is wasted as heat. However, manufacturing these motors is more complex: they require high-quality neodymium magnets and precise winding, which increases initial costs. Mercedes estimates that production cost is currently 30-40% higher than an equivalent radial motor, but expects to reduce it as scale increases.

Origin of the technology

The technology was born in 2009, when engineers from the University of Oxford founded YASA. Before being acquired by Mercedes in 2021 for around 100 million euros, YASA supplied motors to manufacturers like Ferrari, Koenigsegg, and Lamborghini. The challenge for Mercedes was scaling artisanal production to industrial levels, a process that now culminates successfully. YASA had developed prototypes for the Koenigsegg Regera and the Ferrari LaFerrari, but had never achieved large-scale series production. The acquisition by Mercedes allowed access to intellectual property and key engineers, and the company has since invested in automating and optimizing the manufacturing process. A relevant fact is that YASA founder Tim Woolmer continues to lead the development team within Mercedes, ensuring technical continuity. Additionally, Mercedes has patented several improvements in motor design, such as a more efficient cooling system that maintains performance even under high demand. This development is part of Mercedes' strategy to electrify its AMG range, which has historically been synonymous with high-performance combustion engines. The company has announced that by 2030 all its AMG models will be electric, and this axial motor is a fundamental pillar of that transition.

Impact and consequences

This motor promises to redefine electric vehicle performance: more power in less space, allowing for larger batteries or more spacious cabins. However, its mass adoption will depend on costs and scalability. Mercedes plans to initially use it in AMG models, but it could extend to the entire range. Competitors like Tesla are also researching similar technologies, but Mercedes takes the lead in series production. The market impact is significant: the axial flux motor market is estimated to grow at an annual rate of 25% until 2030, according to an IDTechEx report. Additionally, production in Berlin generates employment and reinforces Mercedes' commitment to electrification, at a time when the German industry faces competition from Chinese manufacturers like BYD and NIO. However, there are challenges: dependence on rare earths for magnets could cause supply issues, although Mercedes is researching alternatives like ferrite magnets. Another aspect to consider is durability: axial motors have less inertia and can spin at higher revolutions, which could affect their lifespan. However, Mercedes' internal tests indicate the motor exceeds 300,000 km without significant degradation. Compared to previous events, such as Tesla's introduction of the induction motor in 2012, this advance could have a similar impact on the industry by offering a more efficient and compact alternative.

What readers should know

• The axial motor is more efficient and lighter, but its manufacturing is more complex and expensive for now. Costs are expected to decrease as production increases, reaching parity with radial motors by 2028.
• It is not expected to immediately replace radial motors; they will coexist in different segments. Radials will remain the preferred option for low-cost vehicles and applications where weight is not critical.
• Production in Berlin generates employment and reinforces Mercedes' commitment to electrification. About 500 direct jobs have been created at the plant, and the local supply chain is expected to benefit.
• The first models to use this motor will be high-end AMG models, but Mercedes plans to extend it to the electric E-Class and S-Class in 2026. There is also speculation about its use in the future MMA (Mercedes Modular Architecture) platform.
• Axial flux technology is not exclusive to Mercedes: startups like YASA (now part of Mercedes), Evo Electric, and Magnax are developing similar motors, but Mercedes is the first to achieve industrial-scale production.