In-Wheel Motors Boost Range, Efficiency in EVs

While the pace and market share gains among hybrid electric vehicles (HEVs), plug-in hybrid EVs (PHEVs), and battery EVs (BEVs) may occasionally fluctuate, the overall trend of growth for electrified vehicles and decline for traditional ICE vehicles appears to be firmly established. Overall, the combined share of HEVs, PHEVs, and BEVs in the U.S. market reached a record 21.2% in Q3 2024, driven primarily by BEV sales.

Meanwhile, new competitors, especially those from China, are entering the EV market. They’re attracting attention by offering innovative and technologically sophisticated vehicles that are often more affordable than offerings from existing automakers.

According to the research firm McKinsey, although EV uptake has increased worldwide, it’s always varied by region. In 2024, about 50% of vehicles sold in China were EVs. Of these, 28% were BEVs, 15% PHEVs, and 6% extended-range electric vehicles (EREVs).

EREVs utilize a battery and an onboard combustion engine to extend driving range beyond what’s achievable with a purely battery-powered vehicle. The combustion engine acts as a generator, replenishing the battery when it's depleted, allowing for longer trips without relying solely on charging stations. China is the only market where EREVs are now available at scale.

The adoption of electric vehicles in North America is creating both challenges and opportunities for automotive suppliers. Automakers are increasingly opting for flexible and more affordable solutions for consumers. Soon to join the mix are in-wheel drives that allow for better weight distribution compared to a single motor. They eliminate the need for many of the drive components in traditional vehicles like transmissions, differentials, and axles, which reduces wear and mechanical losses.

Most EV motors are radial-flux (RF) architectures with the rotor and stator sitting one within the other. Here, the magnetic flux between the two runs perpendicular to the axis of rotation, or put another way, “radially.”

A Dual-Rotor, Radial-Flux Motor

Munich-based DeepDrive, an electric motor startup with support from BMW and Volkswagen Group, developed and patented what’s called a dual-rotor, RF motor. In a conventional electric motor, the stator moves either an internal or external rotor. With DeepDrive’s dual-rotor concept, the stator drives both rotors simultaneously. The design allows for an in-wheel drive system, where each wheel hub has its own electric motor (Fig. 1).

The technology can also be used in a traditional, centralized drive system, in which a central motor block powers the vehicle.

With its dual-rotor RF design, DeepDrive’s motor offers advantages over traditional electric motors:

• It’s said to achieve a 20% increase in efficiency, leading to reduced battery size or increased vehicle range. Of note, it delivers improved partial load efficiency, achieving what’s claimed to be industry-leading torque density and power density while keeping material costs low.
• The design significantly reduces the weight of the drive unit by efficiently utilizing rare-earth permanent magnets.
• By deploying this motor at scale, automakers could potentially save over US$1.1bn, significantly reducing the production costs of EVs.
• The motor is claimed to enable EVs to travel more than 500 miles on a single charge.
• It can be seamlessly integrated as a classical central drive system, combined with a gearbox for best performance. Alternatively, it could be implemented as an in-wheel motor and deliver a gearless direct-drive experience. 
• It frees up installation space between wheels, allowing for creative vehicle concepts.
• It’s well-suited for torque vectoring, enhancing vehicle agility and stability. 

DeepDrive’s design is available in multiple voltage models. For example, the DeepDrive RM 1250 in-wheel motor for electric vehicles with 16-in. rims incorporates an integrated SiC MOSFET inverter, automotive standard wheel hub unit, and CAN interface for torque and speed control so that it’s plug-and-play for many electric mobility applications. Other key features include 1,250-Nm peak torque, 80-kW peak power, up to 480-V battery supply, and available with integrated drum brake.

Collaborative Efforts for In-Wheel Motor Integration

According to DeepDrive, eight of the 10 largest global automakers are already collaborating with it, including BMW, which has been testing its prototypes since the summer of 2024. 

In addition to BMW, Continental will integrate its braking systems into DeepDrive's in-wheel motors, creating a motor-brake module for mounting directly on the vehicle wheel. Continental’s Drive-Brake Unit combines an efficient wheel hub motor with an integrated hydraulic brake in the first step, followed by an electromechanical brake in the second step (Fig. 2). Integrating components reduces complexity through modularization and facilitates the manufacturing process.

DeepDrive plans a small-scale launch as early as 2026, followed by large-scale production by 2028-2029. The company will unveil a new range of products for alternative powertrains in September at the IAA Mobility show in Munich taking place from September 9 to 14. 

Survey Results on Personal Mobility and Powertrains

Recently, the IAA (Insurance Auto Auctions) released the results of its Mobility Trend Index, a global survey conducted in the ramp-up to IAA Mobility 2025. The survey queried 1,000 adults (18+) online in China, Germany, France, Italy, Spain, the U.S., and the United Kingdom. It was carried out by the opinion research institute Civey on behalf of the German Association of the Automotive Industry (VDA) in June 2025. 

Findings from the first global IAA Mobility Trend Index clearly showed that personal mobility remains essential across all countries surveyed, and the automobile will continue to play a central role in the future.

At the same time, there’s a broad consensus about the direction of powertrain technology. When asked which type of propulsion is most likely to prevail in the automotive sector, respondents overwhelmingly favored electric drive systems.

The survey also revealed that the automotive industry enjoys a high level of trust worldwide as a driver of innovation and economic prosperity. Particularly notable is the strong willingness to embrace autonomous driving and share anonymized data, especially among respondents in China.