Prototype electric motor reaches 59kW/kg benchmark
(Yarnton, Oxfordshire, UK) October 22, 2025 – YASA, a designer and manufacturer of axial flux motors, smashed its own unofficial power density world record with a new benchmark for ultra-high-performance electric motors, achieving 550kW (738bhp) from a 13.1kg version of its new axial flux prototype motor.
According to YASA, this equals an unofficial power density world record of 42kW/kg, but latest testing of an even lighter 12.7kg version “has significantly exceeded this.”
“Hitting a staggering 750kW (>1000bhp) short-term peak rating, YASA has set a new unofficial electric motor power density world record of 59kW/kg – a 40 per cent increase on initial testing,” according to a company press release. YASA also estimates that its continuous power will be in the region of 350kW-400kW (469bhp-536bhp).
“To achieve a 750kW short-term peak rating and a density of 59kW/kg is a major validation of our next-generation axial flux technology,” said Tim Woolmer, founder and CTO, YASA. “It’s proof of what focused engineering innovation can achieve. And this isn’t a concept on a screen — it’s running, right now, on the dynos. We’ve built an electric motor that’s significantly more power-dense than anything before it – all with scalable materials and processes.”
With three times the performance density of today’s radial flux motors, “YASA continues to redefine the boundaries of what’s possible in electric motor design – turning pure innovation into tangible engineering progress,” says Joerg Miska, CEO, YASA. “Our technology is delivering measurable results today, while paving the way for a new generation of lightweight, efficient electric propulsion systems.”
Find out more at yasa.com