A control system for determining the net power output of an engine associated with a work machine or other vehicle wherein parasitic loads encountered during engine operation are taken into account, the control system including an electronic controller coupled to the engine, at least one sensor coupled to the controller for inputting at least one signal representative of certain operating parameters associated with the engine, and at least one other sensor coupled to the controller for inputting at least one signal representative of the operation of any parasitic load encountered during engine operation, the controller being operable to determine the total output power of the engine and the power requirements associated with any parasitic load based upon the sensor signals. The controller is also operable to output a signal representative of the difference between the total output power of the engine and the power requirements associated with any parasitic loads encountered during engine operation, the outputted signal being used for controlling the operation of the engine or other peripheral equipment or systems associated with the work machine or other vehicle.