YASA just destroyed its own record for power density with its state-of-the-art axial flux motor

Three months after declaring an unofficial world record achievement in power density for an electric motor, YASA’s latest axial flux prototype has shattered that previous benchmark. The axial flux motor specialist is touting another unofficial world record, achieved with an even lighter design.

If you haven’t heard of YASA, we recommend checking out this unique company, which is doing some extraordinary things with electric motors. Over the past 16 years, YASA has evolved in tandem with its technology, revisiting and refining traditional designs dating back to the 1820s by optimizing them with modern components and materials. The result is the axial flux motor – a genuinely viable alternative to conventional radial motors used in most EVs today.

YASA motors have been integrated in production vehicles like the Koenigsegg Regera and the Ferrari Stradale SF90 hybrid. In 2023, we saw the first implementation of YASA’s axial flux motors in a Mercedes vehiclee, the Vision One Eleven concept, after the German automaker acquired the company in 2021.

By late 2024, we saw Mercedes’ first integration of YASA’s axial flux motors into its AMG.EA architecture featuring 800V capabilities and support for dual and tri-motor systems. At the time, YASA said each of its axial flux motors offers four times more torque and double the power of nearly all current tech on the market.

Over the summer, YASA proved the tremendous power of its axial flux motor during real-world trials, achieving an unofficial world record in power density. Now, just a few months later, YASA is touting a lighter motor that delivers significantly more power, declaring yet another unofficial world record.

YASA’s axial flux motors could be a game-changer

To understand the latest milestone recently achieved by YASA, you need to look at the data from its last record-setting trial, which included a 13.1 kg axial flux prototype. As we reported in July, that version was able to achieve a peak rating of 550 kW (738 hp), equating to a power density of 42 kW/kg.

An unofficial world record.

Most recently, however, YASA has been testing a lighter axial flux motor prototype, weighing in at 12.7kg, on a more powerful dynamometer. The latest trials delivered a 750 kW (1000+ hp) short-term peak rating, resulting in a power density of 59 kW/kg – a 40% increase from initial testing and another unofficial world record.

According to YASA CEO Joerg Miska, that’s also triple the performance density of the top radial flux motors currently available in the industry.

Peak power aside, YASA’s latest axial flux motor has the makings of something truly special. The company reported that it estimates the continuous power of its latest prototype to be “in the region of 350kW-400kW (469 hp-536 hp).”

That’s quite impressive when you consider the limited weight and size of such an electric motor and even more exciting when you think of the possibility of four of them (or even two) powering future EVs. YASA founder and CTO Tim Woolmer spoke to the achievement:

On behalf of the entire YASA team, I’m proud and excited to so quickly follow up on the already remarkable results of our initial testing with this incredible result. To achieve a 750 kW short-term peak rating and a density of 59 kW/kg is a major validation of our next-generation axial flux technology. 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. This motor will bring game-changing technology to the high-performance automotive sector.

While these prototypes still have a way to go before reaching scaled production, this latest achievement offers real-life evidence that the technology works and could change the way OEMs approach powertrain design. YASA’s Chief of New Technology, Simon Odling, said it best:

The early results are extremely encouraging. The motor’s performance on the dyno has exceeded even our most optimistic simulations. As well as its incredible peak power and overall power density, we estimate this new motor will be able to deliver all-important continuous power in the region of 350kW-400kW. This is real hardware, in real life, delivering real data – and it’s performing beautifully.

YASA’s team of engineers is already deep into the validation process of this latest axial flux prototype motor, promising further details of its development in the near future.