In-wheel Motor Performance

Ford Motor Company
The Ford Hi-Pa Drive F-150 has no engine; however it does have four in-wheel electric motors that produce more than 600 horsepower.

Producing a vehicle that uses in-wheel electric motors is a process that's a lot more complex than just tearing out the engine and then cramming electric motors into the unused space inside the wheel. This type of electric motor is designed to work on hybrid vehicles, full battery-operated vehicles and even fuel-cell-powered electric vehicles.

The amount of power generated by these in-wheel motors can vary depending on the manufacturer and the size of the motor. For example, a company called PML Flightlink unveiled a Ford F-150 truck at the Specialty Equipment Market Association (SEMA) Show in 2008. PML Flightlink modified the F-150, called the HI-PA Drive, by removing the V-8 engine and adding four in-wheel motors to the truck. The four motors gave the pickup more than 600 horsepower, about twice as much horsepower as it had with the standard V-8 engine. Each motor weighed only 66 pounds (30 kilograms) and gained power from a 1,000-pound (454-kilogram) lithium-ion battery that provided the truck with a range of 100 miles (161 kilometers) before recharging.

The number of in-wheel motors a vehicle actually uses can be adjusted to meet the vehicle requirements. For instance, in most cases, two motors will supply sufficient power; however, if you're talking about an all-wheel-drive (AWD) vehicle -- either an off-road truck or a performance car -- obviously that would require four in-wheel motors.

Up next, let's take a look at Michelin's Active Wheel system to better understand how this technology functions.