AWD: The five types of Subaru systems
Variable Torque Distribution (VTD) All-Wheel Drive:
Legacy 2.5L GT Limited, Outback 2.5L XT and 3.0L R models equipped with the five-speed automatic transmission, and Impreza WRX and Baja Turbo models equipped with the four-speed automatic transmission, feature Variable Torque Distribution (VTD) AWD. An electronically controlled, continuously variable hydraulic transfer clutch works with a planetary gear-type center differential to control power distribution between the front and rear wheels. Under most conditions, VTD uses a 45:55 front/rear torque split, with the rear-wheel bias helping to reduce understeer and contributing to improved handling agility. VTD responds to driving conditions to continually optimize power distribution on all road surfaces.
The VTD system can vary the power distribution as needed in response to traction conditions. It adjusts the front/rear power distribution in the center differential according to weight transfer under acceleration and deceleration (as indicated by throttle input), always sending more power to the wheels with the best traction