This Tiny Electric Motor’s Power Blows The Competition Out Of The Water

Over 700 horsepower from something that’s lighter than the weekly shopping bag.

Photo by: YASA

By: Iulian Dnistran

Jul 22, 2025 at 5:00pm ET

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Yasa’s axial flux motor set an unofficial record for the highest power-to-weight ratio.
During testing, the slim drive unit delivered over 700 horsepower while tipping the scales at just 28.8 pounds (13.1 kilograms).
By comparison, the rear drive unit of a Tesla Model 3 weighs six times as much but makes less than half the power.

A little-known company from the United Kingdom just significantly moved the needle forward in the race to develop lighter and more powerful electric motors. Yasa, which specializes in developing high-performance axial flux electric motors, set a new unofficial record for the highest power density of any electric drive unit.

During routine testing, Yasa’s latest prototype motor hit an astounding 550 kilowatts (737 horsepower) while tipping the scales at just 28.8 pounds (13.1 kilograms). That’s a remarkable power-to-weight ratio of 42 kW/kg.

Yasa axial flux electric motor

Photo by: YASA

By comparison, the ubiquitous Tesla Rear Drive Unit found on the Model 3 and Model Y can output up to 239 kW (320 hp) while tipping the scales at roughly 176 lbs (80 kg). In other words, it makes less than half the power of Yasa’s motor while weighing six times more.

Tim Woolmer, Yasa’s chief technology officer, broke the news late last week on his LinkedIn account, where he added that “there’s more to come.” He said that the impressive result was possible without using exotic materials in the construction of the motor, like cobalt-iron laminations or Litz wire, and that mass production at a “viable cost” is not a far-fetched dream.

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This is big news for the EV industry, where lightness can add a meaningful number of miles to the total range figure. A lighter EV will need a smaller battery to cover the same distance as a heavier car, so costs can go down significantly by using fewer cells.

So far, Yasa’s axial flux motors have been used in very expensive hybrid supercars, like the Lamborghini Revuelto, Ferrari SF90 Stradale, Lamborghini Temerario and Ferrari 296 GTB. However, the lightweight and slim drive units could soon make their way to an all-electric supercar. After being acquired by Mercedes-Benz in 2021, three of the pancake-like motors have made their way into the Mercedes-Benz AMG GT XX Concept, making for a total output of over 1,000 kW (1,360 hp).