A speed control system for a utility vehicle that includes a motor driven drive system. The control system comprises a controller associated with the motor to control the speed of the vehicle up to a set maximum speed. The maximum speed is set to one of at least two different maximum speed values, including a default lower-speed and a high-speed. An input device is associated with the controller and is configured to change the set maximum speed value to the high-speed value only upon entry of a preset passcode.