Quaife ATB LSD F23 FWD Astra G/Zafira A/Vectra BQuaife ATB LSD for F23 FWD gearbox for FWD F23 Astra G Zafira A Vectra B The Quaife Automatic Torque Biasing Differential enables your car to accelerate quicker and corner faster. How? Simply by getting the power to the ground! The differential powers both drive wheels under nearly all conditions, instead of just one. With an normal open differential, fitted as standard on most cars, much precious power is wasted through wheel spin under acceleration.