Apart from being known for incorporating a boxer engine into their models, Subaru is also well known for its Symmetrical all-wheel drive (AWD) system.
What sets the Subaru Symmetrical AWD apart from all other AWD solutions out there is balance.
Balance is achieved by utilizing Subaru's lightweight, compact boxer engine, which is laid out in a straight line in front of the vehicle. Then there's the much heavier transmission, which is located near the centre of the vehicle. By placing the powertrain (engine and transmission in this layout, Subaru models with Symmetrical AWD have an equal weight on all four wheels. As such, thanks to this balance, the moment of inertia is low when braking and turning, which in turns means a more enjoyable driving experience for the driver.
The boxer engine also helps with efficiency, as the engine feeds power directly to the system. Compared to other AWD systems that feeds power to other components before reaching the wheels (which impacts fuel economy and reduces engine power), Subaru's solution is simpler and more efficient, yet is still able to offer a near-perfect side-to-side symmetry.
Just like us humans with equal length feet and hands that allows us to walk properly, symmetry is also found in the driveshafts of the Subaru Symmetrical AWD system, as they are fitted with equal length driveshafts.
Traditional AWD systems with unequal length driveshafts (or front-wheel drive cars) are prone to torque steer, which is an unpleasant experience whereby the steering wheel pulls to one side when accelerating hard (think tug-of-war, but instead with your steering wheel).Torque steer is more evident on more powerful vehicles, as the front wheels have to cope with deploying power and steering. With Subaru's equal length driveshafts, power is distributed equally to all four wheels, eliminating the dreaded torque steer.
Unlike other AWD systems that runs on 2WD mode most of the time, only switching to AWD mode after detecting a loss of traction, Subaru’s Symmetrical AWD sends power to all four wheels at all times, thus improving traction. Because Subaru's Symmetrical AWD have its rear wheels are engaged at all times, it makes the system far more responsive than other AWD systems, but at the expense of poorer fuel consumption.
Boxer engine is, in simple words, it's a very flat, low-mounted engine, and since the heavy engine and transmission are balanced over the front axle, the Subaru Symmetrical AWD system has a low centre of gravity that further improves the vehicle’s handling.
Despite all these benefits, having the Symmetrical AWD system also has its downsides. One of the biggest downsides is the fact that the AWD hardware takes up a lot of space. Because of that, the larger Subaru XV's boot space is about 100 litres less than a smaller Honda HR-V.