That hood scoop feeds air through an intercooler atop its 2.5-liter turbocharged, four-cylinder Boxer engine. Output is given at 305 horsepower at 6,000rpm and 290 pound-feet of torque at 4,000rpm.
The STI uses Subaru's Multi-Mode Driver Controlled Center Differential (DCCD) version of the Symmetrical All-Wheel Drive system. Using a planetary-type center differential -- which is somehow augmented by a mechanical limited-slip type center -- the STI defaults to a rear-biased 41:59 torque split.
After being split fore-to-aft by the center differentials, the torque is again split port-to-starboard by a helical-type limited-slip front differential and a Torsen torque-sensing limited-slip rear differential. I'm counting at least three types of differentials in this MMDCCD system.
Active Torque Vectoring for the STI can apply brake pressure to the inside front wheel to facilitate more neutral cornering and is tied to the Vehicle Dynamics Control (VDC) system.
In the cabin, you'll find black and red trim centered around a new flat-bottom, leather-wrapped steering wheel. Just beyond the wheel, the driver monitors the vehicle's systems with a new 3.5-inch LCD screen in the center of the instrument cluster.
An available touch-screen navigation system features a 6.1-inch LCD screen with voice controls that feeds audio to an optional Harman Kardon audio system.
The WRX STI uses a reinforced six-speed manual transmission. Incline Start Assist can momentarily prevent the car from rolling backward when being driven away from a stop on an incline.
The Subaru Intelligent Drive (SI-Drive) system allows the driver to choose between three selectable modes -- Intelligent, Sport, and Sport Sharp -- to alter the vehicle's performance.
Subaru also announced a 2015 WRX STI Launch Edition. This limited-edition model includes an STI short-throw shifter, Keyless Access & Start, and special cabin trim with blue highlights.
