sentences:  There are several mechanisms that have been developed to vary the torque applied to different sides of a vehicle.These include "clutch-brake" steering, "braked-differential" steering, "controlled-differential" steering, "geared" steering, "Maybach double-differential" steering, "double-differential" steering, "triple-differential" steering, "hydraulic", and electric.In clutch-brake differential steering, power is disconnected to one side or the other with a clutch, and the unpowered side may also have a brake applied to tighten the turn.