Patent ID: 7849953

Claim:
A method for operating a hydrostatically powered vehicle including an engine associated with the vehicle, the engine operatively associated with a fluid pump that is capable of pumping a flow of fluid through at least one hydrostatic propel motor to move the vehicle at a travel speed, the engine operating at a first operating condition, the engine responsive to at least one set of operating conditions that are commanded by an electronic control module, the method comprising: setting a control to a desired fluid flow rate corresponding to a first displacement setting of the pump; propelling the vehicle at a travel speed by passing the flow of fluid through the propel motor; sensing a pressure of the flow of fluid with a sensor and relaying the pressure to the electronic controller; determining a desired operating condition for the engine by the electronic controller based on the pressure of the flow of fluid, the displacement setting of the pump, and at least one parameter from the first operating condition; and operating the engine at the desired operating condition while maintaining the travel speed substantially constant.