In an all-wheel-drive vehicle, engine power can be directed to all four wheels. Subaru Symmetrical AWD differs slightly from model to model in how it directs power to the wheels, depending on its transmission.
A viscous-type locking center differential and limited-slip rear differential help distribute torque – normally configured at a 50/50 split front to rear. If wheel speed differs between front and rear axles, the center and/or rear differentials lock up to help distribute power to the wheels with the most traction.
An electronically controlled variable transfer clutch and limited-slip rear differential distribute power to where traction is needed. Sensors monitor parameters such as wheel slippage, throttle position, and braking to help determine torque distribution and direct it to the wheels with optimum traction.
As with Active All-Wheel Drive, an electronically controlled variable transfer clutch distributes power, but through a planetary-type center differential and a viscous-type limited-slip rear differential. Torque distribution is normally configured at a performance-oriented rear-wheel-biased 45/55 split front to rear. Sensors monitor the same parameters as for Active All-Wheel Drive.
The STI uses an electronically managed multi-plate transfer clutch and a mechanical limited-slip differential in conjunction with a planetary-gear-type center differential to control power distribution between the front and rear wheels. Featuring manual and three automatic modes, DCCD is normally configured at a 41/59 split front to rear. Sensors monitor parameters such as wheel slippage, steering angle, throttle position, and braking to help determine torque distribution and direct it to the wheels with optimum traction. DCCD also features a limited-slip helical front and Torsen® rear differential.
For safety sake, drivers don’t want any surprises from their vehicles when they’re on the road. Having a balanced vehicle that delivers power to the wheels with the greatest traction contributes to driving control. At the same time, this is the type of control that makes a Subaru fun to drive, which is demonstrated by the success that Subaru has had in rally and road-racing championships around the world.
Symmetrical AWD provides safe, predictable, fun-to-drive Subaru vehicles.