the cooling fan speeds associated with the first engine rating and the second engine rating if the commanded engine cooling fan speed is zero then the ecm 15 will use the first engine rating if the commanded cooling fan speed is the maximum command then the ecm 15 will use the second engine rating otherwise if the commanded cooling fan speed is between zero and the maximum speed then the ecm 15 will calculate or otherwise determine an engine rating between the first and second engine ratings as a function of the first and second engine ratings preferably by interpolation the ecm 15 will then use the calculated engine rating to control the maximum power output of the engine thereby permitting the engine to produce an increased amount of overall power to compensate for parasitic power loss resulting from operating the engine cooling fan program control then passes from block 330 to block 340 and program control returns to the calling control loop fig4 generally shows a map 400 of two engine power ratings that may be used in connection with an embodiment of the present invention as described above these engine power ratings may be stored as fuel delivery limit curves as shown in the drawing the map preferably includes a first engine.