Yasa, a Mercedes-Benz subsidiary specializing in axial flux electric motor technology, has recorded what the company believes to be the highest power density achieved by an electric motor across any application sector.
During testing last week, Yasa’s prototype motor delivered 550kW of power from a 13.1kg package, achieving a power density of 42kW/kg. The company states this performance nearly doubles previous industry benchmarks for electric motor power density.
The Oxford-based manufacturer, which has been wholly owned by Mercedes-Benz Group since 2021, employs over 400 people across facilities in Oxford, Bicester and Welshpool. The company develops electric motors and power electronics for premium automotive applications.
Yasa emphasized that the record was achieved without using exotic materials such as cobalt-iron laminations, Litz wire, or 3D printing techniques. The company said the motor design maintains mass production potential, with scalability to 10,000-50,000 units annually at commercially viable costs.
The prototype demonstrated what Yasa described as outstanding thermal performance, with continuous output expected to closely track peak performance levels. The company noted that testing was conducted on standard equipment, with further validation planned on a full-capacity dynamometer later this year.
While the record remains unofficial, Yasa positioned the achievement as significant for practical, high-performance electric motor design. The company indicated this represents the first of several technical announcements planned for release over the coming months, with additional developments expected this autumn and into 2026.
The breakthrough comes as the electric vehicle industry continues seeking improvements in motor efficiency and power-to-weight ratios to enhance vehicle performance and range capabilities.
