Patent ID: 8256281

Claim:
A fuel property determination apparatus for an internal combustion engine, the apparatus comprising: a fuel injection valve for injecting fuel into a cylinder; first injection execution means for executing fuel injection using the fuel injection valve at a first injection timing during an expansion stroke; second injection execution means for executing fuel injection using the fuel injection valve at at least one second injection timing during the expansion stroke, the second injection timing being retarded from the first injection timing, while a combustion cycle proceeds unlike that when the fuel injection at the first injection timing is performed; combustion pressure acquisition means for detecting or estimating a combustion pressure or a correlation value thereof; air-fuel ratio acquisition means for acquiring an air-fuel ratio of an exhaust gas; and fuel property determination means for determining a fuel property based on a combustion pressure during combustion each associated with the fuel injection at the first injection timing and the second injection timing or a correlation value thereof, and an air-fuel ratio of an exhaust gas during combustion each associated with the fuel injection at the first injection timing and the second injection timing.