Patent ID: 7290633

Claim:
A vehicle drive speed control system for a vehicle having driven rear wheels, driven steerable front wheels, and a powertrain for driving the front and rear wheels at controllable speeds, the control system comprising: a steering angle sensor for generating a steering angle signal representing a steering angle of the front wheels; a control unit for controlling the powertain so that a front/rear wheel speed ratio is a non-linear approximately continuous function of the steering angle signal, and the front/rear wheel speed ratio increases as the steering angle increases; and an operator controlled mode select switch connected to the control unit, the mode select switch having operator selectable first and second states, and when the mode select switch is in its first state, the control unit controls the front/rear speed ratio according to a first predefined relationship, and when the mode select switch is in its second state, the control unit controls the front/rear speed ratio according to a second predefined relationship.