Patent ID: 8544444

Claim:
A method of controlling an internal combustion engine system having an internal combustion engine, and a fuel injector which directly injects fuel into a combustion chamber of said internal combustion engine, the method comprising: when a desired torque for said internal combustion engine system is in a first range, injecting a first stage fuel that includes gasoline from the fuel injector into said combustion chamber, wherein the first stage fuel injection ends during a middle stage of a compression stroke at the latest in a cylinder cycle and wherein a first compressive self ignition completes before compression top dead center; determining combustion of the first stage fuel initiated by its compression self ignition; and injecting a second stage fuel that includes gasoline from the fuel injector into said combustion chamber, a second stage fuel amount being greater than a first stage fuel amount, a second stage fuel injection timing corresponding to a first compressive self ignition timing, and wherein a resultant compressive self ignition from the first stage fuel injection and the second stage fuel injection occurs from the first compressive self ignition timing to a timing after compression top dead center.