Abstract: A method of operating an engine having a plurality of combustion cylinders configured to produce an engine output, comprising of adjusting a condition of the engine to achieve combustion by each of spark ignition and homogeneous charge compression ignition, and varying the engine output by at least varying a number of cylinders carrying out combustion.

Abstract: A system for an internal combustion engine of a vehicle is provided. The system comprises a hydraulic pump configured to be powered at least partially by a source other than the engine; an adjustable hydraulic engine actuator configured to be adjusted by hydraulic fluid of the pump; a control system configured to adjust said adjustable hydraulic actuator.

Abstract: A method of starting an internal combustion engine for a vehicle having at least a hydraulic pump configured to be powered at least partially by a source other than the engine and an adjustable hydraulic actuator configured to be adjusted by hydraulic fluid of the hydraulic pump is provided. The method comprises during a first start of the engine, operating with the hydraulic actuator in a first position; and during a second start of the engine, operating with the hydraulic actuator in a second position, said second position different from said first position.

Abstract: A system and method is disclosed for operating a hybrid propulsion system for a vehicle including at least an engine having a plurality of combustion cylinders, wherein the engine is mechanically coupled to at least a drive wheel of the vehicle, an energy conversion device mechanically coupled to at least one of the engine and the vehicle drive wheel, and an energy storage device coupled to the energy conversion device, the method comprising adjusting at least one of the engine and the energy conversion device so that an amount of energy stored by the energy storage device varies within a first range when the engine is operating in a first combustion mode and varies within a second range when the engine is operating in a second combustion mode, wherein the first range is different from the second range.