GM has announced that the Dynamic Skip Fire cylinder deactivation system developed by Delphi (hardware) and Tula (software) will be implemented on the 2019 Sierra.
...DSF is applied to each individual cylinder, and it continuously varies which cylinders must be firing, as it works in sync with the engine’s throttle system. In normal engines, the flap in the throttle body is almost always in a closed position but, with DSF, the flap is nearly always open to control the engine’s power by varying the number of cylinders needed. The cylinders are shut off by stopping the flow of oil with special valve lifters on each cylinder. “The more power you need out of your engine, the more torque, the harder you press down on the accelerator pedal, the greater percentage of your cylinders will fire. This is software-enabled variable displacement,” Tula CEO, Scott Bailey, told Automotive News. Tula says a V8-powered SUV typically only requires 30 hp to cruise on a highway to hold its speed and, with DSF, six cylinders shut down to provide a monumental 21-percent increase in fuel economy, as tested in the real world on a GMC Yukon Denali. Read more: http://gmauthority.com/blog/2015/09/gene.../#ixzz54H15HQ61 ….
...DSF is claimed to be the industry’s first fully-variable engine cylinder deactivation technology…. ...Delphi and partner Tula Technology have revealed test data showing NVH reduction benefits with use of their jointly-developed Dynamic Skip Fire (DSF) cylinder deactivation system that was designed to reduce engine fuel consumption and emissions ....During DSF operation, the decision to fire or skip a cylinder is made immediately prior to each ignition event, with each event considered independently and in sequence. DSF also allows all-cylinder cutoff during deceleration. Many factors are considered when deciding which cylinders to fire; these include torque demand, NVH characteristics of the engine and the frequencies and amplitudes that must be avoided in order to eliminate any impact on occupant comfort….