Patent ID: 7870925

Claim:
A method for managing a powertrain in a vehicle including a front drive wheel, a rear drive wheel, and an electric motor arrangement operable to supply torque to at least one of the drive wheels, the vehicle including a power supply for storing electrical energy and for providing electrical energy to the motor arrangement, the vehicle being operable in at least a first driving mode in which the front and rear drive wheels are selected to drive the vehicle, at least one of the drive wheels having a changeable connection status to the powertrain such that it is selectively connectable to and disconnectable from the powertrain, the method comprising: determining a speed of the vehicle; comparing the speed of the vehicle to a predetermined speed threshold; connecting one of the front drive wheel or the rear drive wheel to the powertrain when the speed of the vehicle is not above the predetermined speed threshold, the vehicle is operating in the first driving mode, and the at least one drive wheel is not connected to the powertrain, thereby connecting both the front drive wheel and the rear drive wheel to the powertrain; and determining if the vehicle is being operated in a city driving mode characterized by at least one of a predetermined number of speed changes of the vehicle over time, changes in a state of charge of the power supply over time, a function of power supply output over time, or vehicle position information, and disconnecting the at least one drive wheel from the powertrain when the speed of the vehicle is not above the predetermined speed threshold, the vehicle is not operating in the first driving mode, a state of charge of the power supply is above a predetermined state of charge threshold, the vehicle is not being operated in the city driving mode, and the at least one drive wheel is connected to the powertrain.