Abstract: A method and apparatus for operating a compression ignition engine having a cylinder wall, a piston, and a head defining a combustion chamber. The method and apparatus includes delivering fuel substantially uniformly into the combustion chamber, the fuel being dispersed throughout the combustion chamber and spaced from the cylinder wall, delivering an oxidant into the combustion chamber sufficient to support combustion at a first predetermined combustion duration, and delivering a diluent into the combustion chamber sufficient to change the first predetermined combustion duration to a second predetermined combustion duration different from the first predetermined combustion duration.

Abstract: A method of operating an internal combustion engine, including at least one cylinder and a piston slidable in the cylinder, may include supplying a mixture of pressurized air and recirculated exhaust gas from an intake manifold to an air intake port of a combustion chamber in the cylinder, selectively operating an air intake valve to open the air intake port to allow pressurized air to flow between the combustion chamber and the intake manifold substantially during a majority portion of a compression stroke of the piston, and operably controlling a fuel supply system to inject fuel into the combustion chamber after the intake valve is closed.

Abstract: A method and system for controlling combustion mode in an internal combustion engine is disclosed. A method for controlling a multi-cylinder internal combustion engine includes operating a portion of the cylinders according to a first combustion mode and operating a second portion of the cylinders according to a second, different combustion mode. The net torque produced by the cylinders equals driver demanded torque. By this invention, a first combustion mode, which has a desirable combustion characteristic such as high fuel economy or low emissions, but which cannot provide driver demanded torque if used in all cylinders, can be used in combination with a second combustion mode, thereby meeting driver demand for torque and gleaning the benefits of the first combustion mode.