Wheelspin

A wheelspin occurs when the force delivered to the tire tread exceeds that of available tread-to-surface friction and one or more tires lose traction.

Standard differentials (also referred to as "open" differentials) always apply equal torque to each wheel. In low traction situations, the total torque delivered to each wheel is limited to the torque that is required to make the wheel with the least traction slip.