Patent ID: 6248041
Filing Date: 2001-06-19
Classification: B60W,F02D,Y02T,Y10T

Abstract:
A method of operating an automotive vehicle comprising an internal combustion engine under the control of an engine control that receives various inputs including a throttle input, that is programmed with data defining different characteristic engine operation functions relating engine torque to engine speed, and that processes the inputs and the programmed data to select a characteristic engine function through which the throttle input acts to operate the engine, the vehicle also comprising a drivetrain that is operable to different drive ratios through which the engine powers the vehicle, such drive ratios including a low drive ratio wherein a ratio of vehicle speed to engine speed is low, a high drive ratio wherein a ratio of vehicle speed to engine speed is high, and an intermediate drive ratio wherein the ratio of vehicle speed to engine speed is intermediate that of the low drive ratio and that of the high drive ratio, the method comprising:when the drivetrain is in the intermediate drive ratio, controlling the engine by causing the control to select a first characteristic engine function characterized by occurrence of peak torque at an engine speed below a rated engine speed at which the torque is less than peak torque, and a speed range that extends beyond rated engine speed to a maximum engine speed of the first characteristic engine function at which the engine outputs substantially zero torque;when the drivetrain is in the low drive ratio, controlling the engine by causing the control to select a second characteristic engine function characterized by occurrence of peak torque at an engine speed below the rated engine speed, and a speed range that extends to a maximum engine speed of the second characteristic engine function at which the engine outputs substantially zero torque and which is greater than the maximum engine speed of the first characteristic engine function;and when the drivetrain is in the high drive ratio, controlling the engine by selecting a third characteristic engine function characterized by occurrence of peak torque at an engine speed below the rated engine speed and of substantial maintenance of the peak torque over a range of increasing engine speeds that includes the rated engine speed and extends to a maximum engine speed of the third characteristic engine function at which the engine outputs substantially zero torque.