Active Fuel Management (formerly known as displacement on demand (DoD)) is a trademarked name for the automobile variable displacement technology from General Motors. It allows a V6 or V8 engine to "turn off" half of the cylinders under light-load conditions to improve fuel economy. Estimated performance on EPA tests shows a 5.5–7.5% improvement in fuel economy.[1]
GM's Active Fuel Management[2] technology used a solenoid to deactivate the lifters on selected cylinders of a pushrod V-layout engine.
GM used the Active Fuel Management technology on a range of engines including with the GM Small Block Gen IV engine family, first-generation GM EcoTec3 engine family, second-generation GM High-Feature V6 DOHC engine family, and first-generation High-Feature V8 DOHC engine family. Vehicle applications included the 2005 Chevy TrailBlazer EXT, the GMC Envoy XL, Envoy XUV, and Pontiac Grand Prix.