Active Fuel Management (formerly known as displacement on demand (DoD)) is a trademarked name for the
automobile
A car or automobile is a motor vehicle with wheels. Most definitions of ''cars'' say that they run primarily on roads, seat one to eight people, have four wheels, and mainly transport people instead of goods.
The year 1886 is regarded ...
variable displacement Variable displacement is an automobile engine technology that allows the engine displacement to change, usually by deactivating cylinders, for improved fuel economy. The technology is primarily used in large, multi-cylinder engines. Many automobile ...
technology from
General Motors. It allows a
V6 or
V8 engine
A V8 engine is an eight- cylinder piston engine in which two banks of four cylinders share a common crankshaft and are arranged in a V configuration.
The first V8 engine was produced by the French Antoinette company in 1904, developed and u ...
to "turn off" half of the cylinders under light-load conditions to improve
fuel economy. Estimated performance on
EPA
The Environmental Protection Agency (EPA) is an independent executive agency of the United States federal government tasked with environmental protection matters. President Richard Nixon proposed the establishment of EPA on July 9, 1970; it be ...
tests shows a 5.5–7.5% improvement in fuel economy.
GM's current Active Fuel Management technology uses a solenoid to deactivate the
lifters on selected cylinders of a
pushrod
A valvetrain or valve train is a mechanical system that controls the operation of the intake and exhaust valves in an internal combustion engine. The intake valves control the flow of air/fuel mixture (or air alone for direct-injected engines) ...
V-layout engine.
Third generation
In January 2018, GM announced an improved version of AFM called ''Dynamic Fuel Management'' to be initially released in Chevy Silverado trucks. This system shuts off any number of cylinders in a variety of combinations, maximizing fuel economy and avoiding switching between banks of cylinders
.
The system is based on ''Dynamic Skip Fire,'' a technology developed by California company Tula Technology. The 6.2L V8 engine of the Chevrolet Silverado incorporating the technology was named one of