A Locking Differential is a differential that can mechanically lock its two output shafts together so both drive wheels turn at the same speed regardless of available traction. Selectable lockers are engaged by the driver through an electric, pneumatic or cable actuator and behave as an open differential when disengaged; automatic lockers engage under torque and ratchet apart when the outside wheel overruns in a turn. Locked, the axle delivers full drive to both tires, which is a decisive advantage where one wheel can lose grip completely. The trade-offs are tire scrub and reluctance to turn while locked, plus abrupt engagement or disengagement that changes handling balance mid-corner, so lockers are far more common in off-road and straight-line use than in road racing.