Assisted steering system for non-trackbound vehicle

A vehicle comprising:

• at least two pairs of wheels having a left and right wheel, at least one of said pairs of wheels being coupled to a steering wheel manipulable into a steering angle for turning the vehicle:
• a plurality of electric drive motors, each respective drive motor being operable to independently drive a corresponding one of said wheels such that during a turn one of said drive motors is associated with an inner wheel and another of said drive motors is associated with an outer wheel;
• and
• steering assisted means for controlling said drive motors in accordance with steering wheel angle, said steering assisting means operating the drive motor associated with the outer wheel at a higher torque than the drive motor associated with the inner wheel to achieve a percentage wheel speed differential between said inner and outer wheels, wherein said drive motors are adjusted at lower vehicle speeds to achieve percentage wheel speed differentials in accordance with a predetermined linear relationship between steering wheel angle and percentage wheel speed differential and at higher vehicle speeds to achieve percentage wheel speed differentials which are increasingly smaller with increasing speed.