Active Fuel Management™ 3.9L V6 and 5.3L V8 Engines

Your vehicle's engine may be equipped with Active Fuel Management. This system allows the engine to operate on either all or half of its cylinders, depending on your driving conditions.

When less power is required, such as cruising at a constant vehicle speed, the system will operate in the half cylinder mode, allowing your vehicle to achieve better fuel economy. When greater power demands are required, such as accelerating from a stop, passing, or merging onto a freeway, the system will maintain full-cylinder operation.