Described herein are various embodiments of an apparatus, system and method for operating a dual fueled spark ignition engine. For example, according to one illustrative embodiment, a method for operating a dual fueled spark ignition engine includes fueling the engine solely with a combustion promoter within a first engine load range between zero and an engine load associated with a target combustion condition selected from the group consisting of rough limit, knock limit, and any of various conditions between the rough limit and knock limit. Within the first engine load range, the amount of combustion promoter fueling the engine increases as the load increases. The method further includes fueling the engine on a mixture of ammonia and the combustion promoter within a second engine load range between the engine load associated with the selected target combustion condition and the engine load associated with a maximum operating pressure of the engine. Within the first engine load range, the amount of ammonia fueling the engine increases and the amount of combustion promoter fueling the engine remains substantially constant as the load increases.