A control process for controlling an engine speed governor of an engine is provided. The process comprises the steps of calculating the current engine power (102) being developed by the engine, and determining an appropriate engine speed (104) for the current engine power based upon a first engine map (105). The process then instructs the speed governor to adjust the engine speed (110) in accordance with the first map (105) if required. The process monitors for desired engine power requests (106), and calculates a power ratio of desired engine power versus current engine power (112) upon receiving a desired engine power request. The process then establishes an engine speed adjustment value based upon a second engine map (113) of power ratio versus speed adjustment value, and instructs the speed governor to adjust the engine speed (114) in accordance with the speed adjustment value. A speed governor system incorporating the control process, and a work machine or vehicle incorporating such a system are also provided.