Patent ID: 7398744

Claim:
A method of operating a 4-stroke internal combustion engine in a first operating mode ( 9 ) which is a compression ignition operating mode, in which an outlet valve of the internal combustion engine is closed at a comparatively early closing time point ( 7 ) with respect to a crank angle (α), and in a second operating mode ( 10 ) which is a spark ignition operating mode, in which the outlet valve is closed at a comparatively late closing time point ( 8 ) with respect to the crank angle (α), comprising the steps of: transferring, during the change of the operating mode from the spark ignition operating mode ( 10 ) to the compression ignition operating mode ( 9 ), the closing time point of the outlet valve in steps, distributed over a plurality of 4-stroke cycles (n), from the late closing time point ( 8 ) to the early closing time point ( 7 ).