A Differential is the geared mechanical assembly that transmits engine torque to the drive wheels while allowing the wheels to rotate at different speeds during cornering. Open differentials send power to the wheel with least resistance — bad for traction. Limited-slip differentials (LSDs) transfer torque to the higher-grip wheel via clutch packs, gears, or viscous coupling. Locking differentials lock both wheels together for maximum traction in straight-line acceleration. Differential choice affects cornering balance and acceleration grip.