Subaru chose to continue their longstanding use of the boxer engine in the Impreza. According to Subaru, their configuration of the engine inline with the transmission minimizes body roll due to the lower center of gravity compared with offset engines in most other vehicles.

 The Subaru layout is also light-weight and lends itself easily to support all-wheel-drive, with power delivered directly to the front and rear wheels, using an integrated transfer case located inside the transmission. The boxer design provides perfect vibration mitigation due to the fact that the movement of each piston is exactly countered by the corresponding piston in the opposing cylinder bank, eliminating the need for a counter-rotating weighted crankshaft (harmonic balancer). Torque steer is also reduced with this type of powertrain layout since the front drive shafts are of equal length and weight.