DETROIT -- An advanced, fast-acting cylinder deactivation system expected to be launched within five years -- probably by General Motors -- could revolutionize gasoline internal combustion engines by firing only the number of cylinders needed.
Dynamic Skip Fire, or DSF, enables a V-8-powered SUV, such as a GMC Yukon Denali, to cruise smoothly and steadily at highway speeds with the engine firing on as few as two cylinders.
That could boost fuel economy by as much as 21 percent and reduce emissions by nearly the same amount.
The technology is being developed by Silicon Valley software startup Tula Technology Inc., which created the algorithm, and General Motors and Delphi Automotive, which have invested in the company and are working with Tula to bring the system to market.
The first vehicles with Dynamic Skip Fire could be on the road by 2020, said Jeff Owens, Delphi’s chief technology officer.
Delphi and Tula officials gave reporters a sneak peek at DSF last week in Detroit and plan to showcase the system this week at the Frankfurt auto show. GM in January announced it was investing in Tula and appears to be first in line to use DSF.
How it works
Today’s cylinder cutoff systems typically shut down half the cylinders on a V-8 or two or three cylinders on a V-6. But DSF is active on all cylinders and it continuously varies those that fire. The strategy enables the engine to maintain proper operating temperature and production levels of smoothness, Tula CEO Scott Bailey said.
Another key difference between today’s cylinder cutoff systems and DSF is how the engine’s throttle system is managed.
Gasoline engines use a flap in the throttle body to regulate the amount of air that enters the intake manifold. The flap’s usual position is nearly closed, causing the engine to work harder to ingest air. DSF keeps the throttle flap almost fully open and controls the engine’s power by varying the numbers of cylinders that fire.