Engine with controlled auto-ignition; selected cylinders are disabled to increase load on remaining cylinders

摘要

A multi-cylinder internal combustion engine 10 is described in which each cylinder is capable of operating within a predetermined auto-ignition load/speed range. Selected cylinders are disabled when the average cylinder load lies below the auto-ignition load/speed range so as to raise the load on the remaining power producing cylinders and enable them to continue to operate within the auto-ignition load/speed range. The decision to commence cylinder disablement may be based on sensed exhaust gas temperature falling below a threshold value. In order to disable cylinder(s), the fuel supply may be interrupted at the same time as increasing the air and fuel supply to the remaining cylinders. The air supply to the remaining cylinders may be increased by VVT control.