Subaru recently rolled out its 14-millionth Symmetrical All-Wheel Drive (AWD) system, marking a historic event for the noted carmaker. Standard to all models except the BRZ, the Symmetrical AWD is an engineering marvel that has proven itself time and time again in the realm of vehicle handling.
Contrary to popular belief, an AWD is not the same as a four-wheel drive (FWD). They may seem to mean the same thing, but they function differently. A FWD provides power to all fours like an AWD; but for a car to turn, the inside wheel must spin slower than the outside wheel. FWD systems normally don’t have that capability, and instead have mechanisms or switches that allow the driver to compensate.
AWD is designed more for maximum stability than maximum traction. Unlike a FWD, an AWD is applied automatically when sensors in the wheel mechanism detects an abrupt change in the road conditions, like a puddle of water or layer of ice. The engine control unit then redistributes the torque to the wheel in contact, a system known as torque vectoring.
The Symmetrical AWD is different in the way it distributes power. Conventional FWD and AWD systems reroute power multiple times before reaching its destination, which means the setup is heavier on one side. Symmetrical AWD positions the Boxer engine directly at one end of the drivetrain, eliminating the need for complex routes. Think of a curved road straightened out.