Chevrolet introduces Dynamic Fuel Management cylinder deactivation on 2019 Silverado; Tula Dynamic Skip Fire
The all-new 2019 Chevrolet Silverado 1500 will offer updated versions of the proven 5.3L and 6.2L V-8s with Dynamic Fuel Management (DFM), based on Tula’s Dynamic Skip Fire (DSF) technology. (Earlier post.) This industry-first cylinder deactivation technology enables the engines to operate in 17 different cylinder patterns to optimize power delivery and efficiency.
Tula’s DSF technology modulates power output by dynamically deciding to fire or skip each cylinder immediately prior to firing. DSF software and engine control algorithms create optimal engine and fuel efficiency by firing only the amount of cylinders needed to match the driver’s request for torque. Because each firing is made at its peak power and combustion efficiency, DSF minimizes fuel use and reduces CO2.
The fully-variable digital cylinder deactivation technology has been developed to the point that it can enable the vehicle to creep ahead in traffic while operating on a single cylinder in the V8.
Chevrolet first introduced its Active Fuel Management (AFM) cylinder deactivation system in 2005, and Dynamic Fuel Management is a natural progression of the technology. Dynamic Fuel Management enables only the cylinders needed to deliver the power you want, seamlessly delivering the best balance of power and fuel economy.—Jordan Lee, Small Block chief engineer
2019 5.3L V-8 DFM VVT DI (L84) for Chevrolet Silverado.
Compared to Active Fuel Management on V8s, which alternates between eight- and four-cylinder modes, DFM features 17 cylinder patterns. That greater authority mixes cylinder patterns constantly to optimize efficiency and power delivery at all speeds.
During an industry-standard test schedule, the 2019 Silverado 2WD with the 5.3L and DFM operated with fewer than eight active cylinders more than 60% of the time, 9% more than a comparably equipped 2018 model with AFM.
DFM is powered by a sophisticated controller that continuously monitors every movement of the accelerator pedal and runs a complex sequence of calculations to determine how many cylinders are required to meet the driver’s requested torque. It can make this determination 80 times per second.
An electromechanical system deactivates and reactivates all 16 of the engine’s hydraulic valve lifters, controlling valve actuation. The system uses solenoids to deliver oil pressure to control ports in the lifters, which activate and deactivate the lifters’ latching mechanisms. When a cylinder is deactivated, the two-piece lifters effectively collapse on themselves to prevent them from opening the valves. When the cylinder is reactivated, solenoids send an oil pressure signal to the control ports on the lifters and the latching mechanism restores normal function, allowing the valves to open and close.
The increased variability of Dynamic Fuel Management means the engine will operate more often with a reduced number of cylinders, which saves fuel across the board. Better yet, the transitions are transparent, and because the system is torque-based, you’ve always got that satisfying feeling of power on demand that comes from Chevy’s Gen V Small Block V-8 engines.—Jordan Lee
The 5.3L V-8 with DFM is SAE-certified at 355 horsepower (265 kW) and 383 lb-ft of torque (N·m) and is matched with a Hydra-Matic eight-speed automatic transmission.
The 6.2L with DFM—the largest and most powerful gas V-8 in the segment—is SAE-certified at 420 horsepower (313 kW) and 460 lb-ft of torque (623 N·m) and is paired with a Hydra-Matic 10-speed automatic transmission.
Both transmissions feature enhancements designed to improve shift quality, as well as a new centrifugal pendulum absorber torque converter that reduces vibrations to improve smoothness, particularly during cylinder deactivation events.
The engines also feature driver-selectable stop/start technology that helps save fuel in stop-and-go traffic. The 5.3L version is standard in LTZ and High Country models and available on LT, RST and Trail Boss. The 6.2L is available in LTZ and High Country. Both engines will be built at General Motors’ Tonawanda Engine Plant in Buffalo, New York.
Active Fuel Management also is employed on the Silverado’s standard 4.3L V-6 and E-85-capable 5.3L V-8.
The 2019 Silverado goes on sale this fall. EPA fuel economy estimates and towing/payload capacities are not yet available will be announced closer to launch.