An agricultural work machine, such as a harvester, is disclosed. The agricultural work machine includes an internal combustion engine, at least one working assembly, and a regulating device. The internal combustion engine provides power to the working assembly, with the internal combustion engine being operated in different power settings, with a different performance characteristic in each of the different power settings. The regulating device causes automatic shifting of the internal combustion engine from one power setting to another in response to determining that the power requirements assigned to the working assembly change. The power settings may be assigned to different, pre-selectable power setting ranges, which may differ in terms of the highest respective power setting assigned thereto. Further, the regulating device may only cause shifting of the internal combustion engine between power settings in the respective pre-selected power setting range.