A steering system (10) for a vehicle including a steerable wheel (12)
defining a steering angle (20), a powered actuator (14) controlling the
steering angle (20) and a steering wheel (16) providing a driver input
control angle. A ratio of the driver input control angle to the steering
angle (20) defines a steering ratio. The steering system (10) also
includes a controller (18) selectively varying the steering ratio that
directs the powered actuator (14) to change the steering angle (20) along
one of at least two steering ratio graphs, and a control (60) manually
selectable by a driver of the vehicle that communicates with the
controller 18 for selecting one of the steering ratio graphs. A first one
of the graphs (50) varies as a function of the driver input control angle
in a manner that is different than that of a second one of the graphs
(52).