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Cylinder Deactivation

Cylinder deactivation (also known as displacement on demand, variable displacement, multiple displacement system, or active fuel management) uses engine control systems to shut off the air-fuel mixture to some of the engine’s cylinders when they are not needed. For example, cruising at highway speeds takes less horsepower and torque than accelerating. When additional power is not needed, the intake and exhaust valves on half the engine’s cylinders close. When the valves are closed, fuel is not being burned in those cylinders.