- Lighter, more powerful and more affordable in-wheel motors are on the horizon
- Elaphe Propulsion Technologies unveiled a 2,000 hp supercar concept
- Donut Lab says its motors can power a variety of products
Most modern electric cars use an electric motor that drives either the front or rear axle – or both if equipped with four-wheel drive and two motors. This works just fine, but it’s not the most efficient solution, as energy (and thus battery range) is lost due to mechanical friction via the transmission, drive shafts and more.
Furthermore, car designers and engineers are relatively limited in the way they can package new vehicles, having to shoehorn in the necessary plumbing for a bulky electric powertrain.
The next big thing in EV-land is the introduction of in-wheel motor (IWM) technology, which has been around for decades but has taken a long time to refine to a point where it can be affordably and realistically introduced into production cars.
Donut Lab, a subsidiary of Verge Motorcycles—the futuristic electric motorcycle brand that pioneered in-wheel motor technology in high-performance two-wheeled transportation—showcased the latest generation of its technology at this year’s CES 2025, and it has potential to change the game again.
In-wheel motor technology has been considered too expensive, underpowered and too bulky for mass-produced cars, as a huge amount of weight is essentially placed in one area (the wheels) that needs to be as light as possible – a concept called the ‘unsprung mass’ of cars, which refers to anything not supported by the vehicle’s suspension system.
It plays a critical role in how a vehicle handles, but Donut Lab says its latest motor technology can be as light as 40kg yet deliver a power-to-weight ratio that far exceeds anything currently available is on the market. Unsprung mass becomes a moot point.
The company’s managing director, Marko Lehtimäki, says that a 21-inch version with car-specific specifications can deliver a powerful 630 kW of power, which is 845 hp. Multiply that number by four, and the next generation of supercars can easily produce 3,380bhp if manufacturers can figure out how to transfer that power to the road below.
Silly supercar daydreams aside, the technology is more likely to be used in a more restrained way, with a pair of lightweight and less powerful in-wheel motors driving the rear wheels, which can still produce a heady 600-800bhp without the associated costs.
There is a 17-inch motorcycle application that produces around 200 hp (it’s up there with most modern superbikes) that weighs just 21 kg, while a 12-inch version weighs just 8 kg.
Lehtimäki says his company has managed to extract class-leading performance with “a smaller amount of active materials”, meaning manufacturers can jump on board with the motor-in-wheel and save as much as 50 percent in production costs compared to traditional EV motors.
Analysis: The wheels are in motion
Donut Lab weren’t the only in-wheel motor pioneers exhibiting at CES this year, as Slovenian company Elaphe Propulsion Technologies also showcased its ultra-thin Sonic 1 hardware capable of developing 268 hp while enough room in a 21-inch wheel. for standard high-performance disc brakes.
This would make the engines suitable for use in high-performance driving situations, such as on the racetrack, where reliable and predictable braking power is essential.
The company showcased its technology in the Italdesign Quintessenza concept, which takes the form of a futuristic electric pick-up/SUV hybrid that packs a Sonic 1 motor in each wheel for over 2,000 hp.
Elaphe says it is working on mass production concepts that it hopes it can develop with OEMs. However, don’t expect to see a production version until 2030 or later.
Despite these long time frames, the race is on to be the first to introduce in-wheel engines to the buying public. BMW announced last year that it was working with Munich-based electric motor engineers DeepDrive to develop in-wheel motor technology that could be scaled to a point where it makes economic sense for mass-produced electric cars.
Similarly, serial innovator Hyundai Motor Group has been working on and refining its ‘Uni Wheel’ technology since 2023.
There has been no update on the latest progress, but the Korean company said the technology could completely change the way it packages electric cars in the future, helping it improve battery range and massively increase the durability of its power units.
