An internal combustion engine includes a first fuel injector configured to inject a first fuel into an engine cylinder in response to a first injection signal, a second fuel injector configured to inject a second fuel into the engine cylinder in response to a second injection signal, and a third fuel injector configured to inject a third fuel into the engine cylinder in response to a third injection signal. The first, second and third fuels have different reactivities. An electronic controller provides, as appropriate, first, second and third injection signals using an engine speed and an engine load signals as primary control parameters such that the engine operates in at least two different combustion modes.