Improved Fuel Efficiency
The wheel bearing also has a unique aspect of affecting fuel economy. As an example, by reducing the friction between the rotating elements of a wheel and axle, bearing allows the former to rotate more freely with lesser energy demands. With less fuel being used, power is generated more easily by the motor free of this taxing process (and some will return to assist with propelling the vehicle forward). This means saving money for the person driving, and it also saves ecology. This is the converse of a driver being very economical -- less fuel per miles travelled is less environmental harm.