All commonly used speed sensitive power steering assist systems for cars are based on hydraulics. These systems [ILLEGIBLE]ange the pressure or modulate the flow of the conventional [ILLEGIBLE]draulic power steering system. They require some means of [ILLEGIBLE]ctuation in the form of an electromagnetic device such as a solenoid actuator working as a flow pressure regulator or brushless motor driving a hydraulic pump. Usually they are pulse width modulated controlled by a microprocessor. Therefore, these systems can be quite complicated.This paper describes MAGNASTEER a novel magnetic speed sensitive system developed at General Motors Corporation.The effort variation provided by MAGNASTEER is the result of an electronically controlled electromagnetic torque, which acts as an addition or subtraction to the torsion bar torsional rate, effectively varying the feel of the hydraulic system. Unlike some other variable effort spped-dependent systems based on hydraulics, the MAGNASTEER systems doesn't require additional components such as sensors, hydraulic pump controls or additional hydraulic plumbing. This simple and highly reliable systems doesn't interfer with the existing hydraulics, and is fully integrated into the system.