The fourth generation WRX body design took a stronger departure from the Impreza donor model than in the past. The general WRX profile/silhouette was carried over from the Impreza, as were the front doors, trunk lid, and interior. However, the entire front end bodywork plus the rear quarter panels were unique to the WRX. The rear doors received a subtle reskin with an upwards kink and revised character line, but retained an otherwise identical shape.
This model was the first of the WRX line to not use the EJ-series engine, now featuring the new 2.0-liter FA20F engine, which has direct injection and a twin-scroll turbocharger. On all previous WRXs the turbocharger was located near the right-hand side of the firewall, close to the third cylinder. With the new FA20F, Subaru fitted the turbocharger at the front of the car, close to the serpentine accessory belts. There is a robust aluminum skid plate that protects the underside of the turbocharger. Mounting the turbo lower in the engine bay helps reduce the car’s center of gravity. The FA20’s high compression ratio of 10.6:1 combined with its 68° intake and 54° exhaust cam phasing range allow it to produce excellent off-boost efficiency as well as a wide torque peak.