Our earlier excitement about a radical electric motor innovation—axial flux motors—is aging remarkably well. Recent news from Mercedes-Benz, which acquired UK-based motor pioneer YASA, suggests these motors are officially leveling up: lighter weight, higher performance, and lower cost. The first stop? Luxury EVs. If scaling plays out, expect much more widespread adoption later.

If you’ve never seen one, the design looks like someone shrank a normal EV motor vertically and stretched it sideways—basically a giant metal pancake. The key shift is in how magnetic flux moves: axial designs rotate flux 90° from conventional radial flux motors, resulting in a thin, wide geometry rather than a long cylinder.

What Makes Axial Flux Motors Such a Big Deal?

Here’s the nutshell version: more power, less weight, smaller footprint.

EV manufacturers care about that combo for obvious reasons, and YASA’s latest numbers are kind of bonkers. According to Steve Hanley at CleanTechnica:

“Earlier this year, UK-based YASA amazed the world by showing off an axial flux electric motor that weighed just 13.1 kg (29 lb) and was rated at 550 kW (738 hp), for an energy density of 42 kW per kg. Now it is back with a new and improved version… that weighs less — 12.7 kg (28 lb) — and is capable of a staggering 750 kW (1018 HP) peak power… surely a world record for energy density at 59 kW per kg.”

That’s wild—especially for something the size of a stack of dinner plates. 

The EV Weight Savings Are Even More Interesting

Switching from radial to axial flux motors isn’t just about impressive power density. There’s a cascade of weight reductions that ripple through the vehicle:

• The motor itself is lighter and flatter

• Supporting components (brakes, suspension, chassis) can shrink

• Smaller battery packs may be enough thanks to efficiency gains

Knocking 200–500 kg out of a vehicle is not out of the question, and less mass means improved range, faster acceleration, and better handling. It’s a compounding benefit rather than a single upgrade.

Designers also get more packaging flexibility since these motors don’t dictate the same long cylindrical layout.

Torque, Cooling, and Efficiency: Axial Flux Has Physics on Its Side

According to Wikipedia, axial flux geometry also brings a torque advantage:

“With axial flux geometry, torque increases with the cube of the rotor diameter, whereas in a radial flux the increase is only quadratic.”

More torque is a very big deal for trucks, commercial EVs, and performance EVs.

Axial motors also have:

• More magnetic surface area

• Greater cooling area for a given volume

Those two factors drive better thermal management and sustained performance—an Achilles heel for many current EV platforms.

What About Materials and Rare Earths?

YASA claims it avoids “exotic materials,” which may help on the sustainability and supply chain fronts. They don’t explicitly say there are zero rare earths, but any reduction matters. Between cost pressures and geopolitical concerns, “less rare earth” is becoming a competitive advantage in EV motors.

Where This Might Be Heading

Mercedes’ adoption of this technology is a strong signal. Luxury EVs tend to get the cutting-edge parts first, but if costs drop—and there’s good reason to think they will—axial flux could reshape how motors are packaged across the industry.

If this architecture takes hold, we could see lighter, cheaper, more efficient electric cars in the not-too-distant future. Trucks might benefit even more thanks to the torque density.

If you want a visual dive, there’s a YASA explainer video with excellent graphics that really helps make the performance jump clear. It’s worth the watch if “pancake motors” are new to you.