Reduced pumping losses
In spark ignition, engines reduced pumping losses result in increased fuel economy.
Early Intake Valve Closing (EIVC) closes the intake before bottom dead center (BDC) to decrease pumping loss at the valve. We use low lift event for most of low speed operation and it’s always used with cam phasing for optimum timing of low lift.
Cylinder deactivation closes intake and exhaust valves on specific cylinders and forces the remaining cylinders to perform higher specific work. These higher loads force the throttle to be opened more, reducing pumping loss in the active cylinders and improving fuel economy.