Active Fuel Management (AFM) is the deactivation of four of the LT1’s eight cylinders, allowing the V-8 to run as a V-4 when the load on the engine is low. This technology typically boosts fuel efficiency between 5.5 and 7.5 percent. Shown here is the Lifter Oil Manifold Assembly (LOMA), which sits where the lifter valley cover does on the old LS3. A series of solenoids opens and closes lube passages to the lifters on four cylinders. When charged with oil pressure, the lifters activate the valves in their respective cylinders, but when closed, the cylinder is deactivated. This deactivation is coordinated with the shutoff of fuel.