THE STi's engine is always a standout feature given its higher power output than the standard WRX, but also because of the introduction of variable valve timing this time around, which aids driveability. The front torque-sensing limited slip differential is a new addition to the STi's spec sheet and succeeds in making the car an even faster point to point proposition than it was previously. It enables the STi to break free of the shackles of understeer when exiting a corner under power and also helps the super Sube to keep pace with its main rival, Mitsubishi's Lancer Evo, which employs a high-tech four-wheel drive system with Active Yaw Control to dial out understeer and oversteer through the front and rear differentials.