Yasa, the British electric motor specialist owned by Mercedes-Benz, has developed a prototype motor it claims sets a new benchmark for power density in electric propulsion. The axial flux motor reportedly delivers 550 kilowatts of output while weighing just 13.1 kilograms, achieving a power density of 42 kW/kg.
The figures were shared by Yasa’s Chief Technology Officer Tim Woolmer in a recent LinkedIn post. Although no formal statement has been issued by Yasa or Mercedes-Benz, Woolmer described the performance as “a new world record,” noting that the feat was achieved “unofficially (and a little accidentally!)” during internal testing.
According to Woolmer, the motor sustained 670 volts and 850 amps over a five-second interval. The quoted weight includes all essential mechanical components, such as magnets, housing, rotor structure, and shaft. “This is not a lab experiment,” he added, emphasizing the motor was built using standard production materials rather than exotic composites. “It’s scalable to sports car volumes (10–50k units/year) at a viable cost.”
Yasa, based in Oxford and acquired by Mercedes-Benz in 2021, specializes in compact axial flux motors known for their high efficiency and compact form. The firm’s technology has already appeared in Mercedes concept vehicles, including the Vision One-Eleven and the recently revealed AMG GT XX, which incorporates three axial flux units promising up to 1,000 kW of combined output.
Woolmer did not confirm whether the prototype is the same model used in the AMG GT XX, but hinted at ongoing development. “More to come – many thanks to Drive System Design for pushing their dyno above the 500kW limit,” he wrote. “We’re not done yet – we get on the ‘big dyno’ this summer.”
