[Shane@DBPerformance]

Stolen from the interwebs...

A Standard limited slip diff, as fitted to the
majority of cars allows the two driven wheels to rotate at different speeds while delivering the same torque to each wheel. The wheels need to travel at different speeds when the car is cornering as the outside wheel has to travel a greater distance than the inside wheel.

This system works fine in most daily driving situations but this system has faults which will become more apparent on slippery surfaces. For example when driving on snow, one wheel may have little or no traction and hence the torque created is negligible and as the diff
transmits the torque 50/50 between the two wheels, the other wheel gets 50% of next to nothing which is why the car will not move forward.