Posted on 8/4/2023
Active Fuel Management (AFM) is General Motors version of a cylinder deactivation system. Cylinder deactivation is used to increase fuel economy of higher displacement engines while cruising down the highway in light load conditions when the extra power is not needed. During light load conditions the PCM (Powertrain Control Module) can shut down predetermined cylinders by disabling the camshaft lifters and shutting off the fuel injectors. Which prevents those cylinders from consuming incoming air and fuel. Thereby reducing fuel consumption. Think of it this way. First, you give your teenager a soft drink with a large straw. The pop consumption will increase. Now if you give the same kid the soft drink with a tinny tiny coffee straw the pop consumption will decrease. Why not just keep it simple and install small engines in all vehicles? Well, a four-cylinder engine in your pick-up or large SUV would leave you craving additional power when accelerating. Add a trailer to that same vehicl ... read more