How In-wheel Electric Motors Work and Their Advantages

In-wheel electric motors have been around for years, but very few actually understand what they are. Recently, however, they’ve sparked renewed interest from auto manufacturers and tire companies alike because of their potential to improve the efficiency of electric vehicles (EVs).

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Pro Tip: Right now, in-wheel electric motors are used by little known platforms such as Aptera (a three-wheeled solar-assisted EV), Lightyear One (a four-door sedan that incorporates solar panels into its body to extend its range), Nikola Tre ( a hydrogen fuel cell truck that aims to compete with Tesla’s Semi), and Ree Automotive, which makes modular EV chassis that can be customized for various different types of commercial vehicles.

What Is an In-wheel Electric Motor?

Just as its name suggests, in-wheel electric motors are motors installed in each of the driving wheels. They’re a type of EV drive system that replaces the gasoline engine with an electric motor.

How Do In-wheel Electric Motors Work?

Conventional EVs typically make use of the same automotive technology as gasoline vehicles, except for their electric motor built into the driveline rather than receiving power from an Internal Combustion Engine (ICE).

Electric motors transfer power to the wheels through shafts of various lengths depending on the platform, which results in a slight (unnoticeable) torque delay. An in-wheel motor completely changes the game by getting rid of that delay.

Because they’re installed close to each of the drive wheels, in-wheel motors transfer power to the wheels through extremely small drive shafts. The time lag is significantly reduced, which is among the many advantages of these motors.

What Are the Advantages of In-wheel Electric Motors?

As hybrid and electric cars gradually take over public roads, it’s no surprise that the prospect of using in-wheel electric motors has risen. Here are some pros that make these motors popular:

Impressive Horsepower

One of the key selling points of in-wheel motors is their high power output. A single in-wheel motor can produce over 147 horsepower, which means a combination of four in-wheel motors can produce around 600 horsepower.

Some say the increased horsepower of in-wheel electric motors coupled with the reduced weight of hybrids can produce great performance. Note, however, that this may not be true all the time. While hybrids are somewhat lighter than gas-powered vehicles, EVs weigh more than conventional vehicles because of the weight of the batteries.

While hybrids are somewhat lighter than gas-powered vehicles, EVs weigh more than conventional vehicles because of the weight of the batteries.

–Richard McCuistian, ASE Certified Master Automobile Technician

• The curb weight of  a full size Ford gas engine pickup is 4,603 lbs.
• The curb weight of a full size Ford hybrid pickup is 3,636 lbs.
• The curb weight of a Ford Lightning Electric pickup is 6,500 lbs.

Improved Torque Response

When it comes to response time and performance, torque is one of the biggest factors to consider. Cars with in-wheel electric motors produce plenty of torque in an instant. Unlike vehicles with combustion engines, the motors transfer the force directly to the wheel. This means there’s less torque loss and a faster response time.

Regenerative Braking

Some in-wheel motor designs come with a regenerative braking system that redirects the car’s kinetic energy into electricity. Whenever you hit the brakes, the kinetic energy that was propelling your car forward suddenly dissipates into heat. It’s wasteful, but it’s not something you can help.

Increased Fuel Efficiency

If you want to use less fuel for your hybrid car, you’ll have to keep its battery charged for as long as possible. Electric in-wheel motors can help with that, thanks to their regenerative braking system. Every time you hit the brakes, you’re recharging your car’s battery, reducing the need for the vehicle to use gas.

Additional Design and Structural Enhancements

In-wheel electric motors get rid of the need for an engine, which opens up more opportunities for design and structural enhancements. Automakers have greater creative freedom over vehicle designs, manufacturing processes, and other developments.

Better Handling

Individual wheel motors provide better torque distribution, which significantly improves driver handling. You’ll experience enhanced stability and control over the vehicle as well as improved traction control.

Greater Driving Range Than Other Type of Electric Vehicles

With in-wheel electric motors, hybrid and electric cars have a much better driving range. The motors remove efficiency losses due to gear, differential, and constant velocity (CV) joint issues. The total weight of the car is also reduced. Because of these factors, you can drive longer with hybrid and electric cars than cars without in-wheel electric motors.

What Are the Disadvantages of In-wheel Motors?

In-wheel motors may be great, but they aren’t perfect. Some manufacturers question their durability and effects on the suspension. Think about it: is there any other part that’s as exposed to the elements as your vehicle’s wheels are?

Wheels constantly take impact from the road, and all those vibrations can cause wear on even the sturdiest wheels. Placing motors there makes them more vulnerable to the elements.

Despite these disadvantages, however, manufacturers and consumers alike find themselves drawn to the technology behind in-wheel motors. The advantages are no doubt attractive too. It’s clear that people look forward to how in-wheel motors are going to boost hybrid cars and EVs in the future.