The global in-wheel motor market is projected to grow at a CAGR of 35.02% during the forecast period to reach USD 2,641.1 million by 2025 from an estimated USD 322.8 million in 2018. In-wheel motor improves the performance of electric vehicles. It replaces transmission, drive shaft, axles, and differentials. In-wheel motor helps supply torque to its associated tire and generates more power to improve the efficiency of a vehicle.
The BEV segment (zero emission vehicles) is set to register the highest growth rate of the in-wheel motor market, followed by HEVs and PHEVs because of the availability of better subsidies and support from governments. Increasing vehicle range has fueled the demand for BEVs. The top 5 selling BEV models in Europe are Renault Zoe, Nissan Leaf, Tesla Model S, BMW i3, and Volkswagen e-Golf. Tesla Model S, Chevy Volt, BMW i3, and Nissan Leaf are equipped with in-wheel motors. Further, NTN developed the “Two Motor On-board Drive System” for the next-generation electric vehicles, which powers the left and right wheels along with the motors on each wheel.

The electric passenger car segment is estimated to be the largest of the global in-wheel motor market in 2018. The market growth of in-wheel motors can be attributed to factors such as improved fuel efficiency, high torque, increased power, and provision of better vehicle handling to both new and existing vehicles. The increasing support from governments in China, Japan France, Norway and the US, and the OEM’s efforts to improve the existing EVs models are expected to drive the sales of electric vehicles Passenger Cars (PCs) during the forecast period, which in turn would boost the demand for in-wheel motors for passenger cars.

Asia Pacific is the largest in-wheel motor market. China is the largest market because the Chinese government provides huge subsidies for the electrification of vehicles. Increase in sales of electric vehicles will lead to the increase in sales of in-wheel motors as only electric vehicles are equipped with in-wheel motors. For instance, Protean Electric, which is known for its in-wheel motors, will form a joint venture with Weifu High-Technology Group in China, and the company will try to commercialize its ProteanDrive Pd18 Motors on a larger scale.

Government support for electric vehicles, increased driving range, reliability, and improved vehicle performance are creating opportunities for the growth of the in-wheel motor market
Axial Flux Motor
Axial permanent magnet wheel motor is generally used for compact electric vehicles. An electric vehicle is driven directly by 2 wheel motors installed on its rear wheels. An axial flux motor is compact, lightweight, and highly efficient. It is used to increase the output torque and efficiency. It can be used as direct drives in electric vehicles. The manufacturing and assembling processes are simple compared to radial flux motors.

Radial Flux Motor
Radial flux motor is the most common type of motor adopted for in-wheel motors as the rotor can be directly fixed to the wheel. Moreover, in radial flux motors, the outer rotor design is about 15% lighter than the inner rotor machine, which generates the same torque due to their longer air gap diameter. In-wheel motors are almost radial because of the integration benefits, durability, and torque density.

Passenger Cars
A Passenger Car (PC), as defined by the OICA, is a motor vehicle equipped with at least 4 wheels, comprising not more than 8 seats. The PC segment is the largest, by vehicle type, and includes sedans, hatchbacks, station wagons, Sports Utility Vehicles (SUVs), and Multi-Utility Vehicles (MUVs). This vehicle segment is the most promising market for electric vehicles as it is the largest segment in the automotive industry. The PC segment of the electric vehicle market is growing at a significant rate in emerging economies in the Asia Pacific region. The market growth in the region can be attributed to a rise in the GDP and population, improvement in lifestyle, increased purchasing power of consumers, and development of infrastructure.

Commercial Vehicles
The commercial vehicle (CV) segment includes LCVs and HCVs. HCVs combine 2 categories of vehicles—heavy trucks and buses and coaches. The nature of these vehicles limits their production volume and growth rates as they are used in specific applications such as logistics, construction, and mining industries. On the other hand, LCVs have come a long way from having bare essential features to full-blown utility vehicles that can be used for passengers as well as commercial purposes.

Air Cooling
The in-wheel motors, which have a peak power of 30 KW, can be cooled using the air cooling method. For instance, Elaphe provides LEV in-wheel motor that has a peak power of 20 KW, with a speed of 1,200 rpm, which can be cooled by the air cooling method. The in-wheel motors which are cooled by the air cooling method deliver a high torque, which enhance the performance of the vehicle. It is mainly used for light electric vehicles and city electric cars.

Liquid Cooling
The in-wheel motors, which have a peak power above 30 KW, can be cooled using the liquid cooling method. For instance, Elaphe provides L1500 in-wheel motor that has a peak power of 110 KW, with a speed of 1,250 rpm and can be cooled by using the liquid cooling method. The in-wheel motors which are cooled by the liquid cooling method are powerful, compact along with standard disc brake and outer caliper. It is mainly used in SUVs and powerful sedans.
Critical Questions:
Where will the autonomous vehicle technology take the industry in the long term?
Will the industry cope with the challenge of high cost of the in-wheel motor market?
How do you see the impact of the additional weight of in-wheel motors?
The major restraints considered in the study include high price and increase in unsprung weight in wheels, which restrict the sales of in-wheel motors.

The global in-wheel motor market is dominated by major players such as Protean Electric (US), Elaphe (Slovenia), ZIEHL-ABEGG (Germany), Printed Motor Works (UK), and NTN (Japan).