SINCE 1997, EVERY SUBARU VEHICLE SOLD IN THE UNITED STATES HAS BEEN EQUIPPED WITH ALL-WHEEL DRIVE. TODAY, SUBARU SYMMETRICAL ALL-WHEEL DRIVE (AWD) IS ONE OF THE SUBARU CORE TECHNOLOGIES.
In 1972, Subaru introduced its first AWD vehicles. During the intervening years, Subaru has continuously improved its AWD technology. Today, this technology enhances traction, control, and balance, contributing to vehicle safety as well as performance.
Giving the Subaru system an added edge is its symmetry. Subaru designs and engineers drivetrain components for balanced front-to-rear and side-to-side operation.
Here is what comprises Subaru Symmetrical AWD, using Outback as an example. The main system components are the engine, transmission, transfer case, propeller shaft (driveshaft), and rear differential – all parts of the drivetrain.
Notice how the engine is laid out longitudinally – that is, in the direction of the length of the vehicle. Two axle shafts emerge from the transmission housing, one on either side. Otherwise, there are no external shafts driving the front wheels outside the transmission housing and transfer case.
The two sides of the Subaru layout are mirror images of each other. They’re balanced – symmetrical. However, despite the mechanically attractive appearance of Symmetrical AWD, Subaru didn’t engineer it for aesthetics. There are practical reasons for such a design.
Examination of other manufacturers’ AWD vehicles reveals that a good many of them have transversely mounted engines that necessitate changing the direction of torque from the engine by 90 degrees. These are primarily front-wheel-drive vehicles with rear-wheel drive added, usually as an option.
Even vehicles with longitudinally mounted engines tend to have external driveshafts for the front wheels, along with other components outside the centrally located powertrain.
The Subaru design is simpler and cleaner. It lends to a balanced, predictable driving experience and improved driving control.