In-wheel motors improve fuel economy and safety The electric motors in hybrid vehicles do a lot to save fuel and cut emissions, providing the push that gets a hybrid going from a dead stop and the extra getâ''up-and-go for rapid acceleration or hill climbing. They also recapture some of the energy that goes to waste every time a driver applies the brakes. But engineers would like to make hybrids even more efficient by further exploiting the electric motor's virtues. One way is to increase onboard electricity storage so none but the longest trips require turning on the gasoline engine at all. Another approach is to eliminate the losses that occur as the torque generated by the motor is transferred to the wheels.
Several companies are proposing to curb these losses by squeezing electric drive motors into the wheels [see diagram, ”A Different Spin”]. Generating propulsion power right where the rubber meets the road makes a surprisingly big difference.