GM expects 15% mpg gain from new cylinder deactivation system
[/link]GM expects 15% mpg gain from new cylinder deactivation system
January 5, 2015 - 11:00 am ET
DETROIT -- General Motors says a new infinitely variable cylinder deactivation system it has been developing with a Silicon Valley start-up can boost the fuel economy of gasoline engines by as much as 15 percent.
Called Dynamic Skip Fire, or DSF, the ignition system technology integrates advanced digital signal processing and software to selectively fire the engine’s spark plugs based on driver demand. DSF creates an infinitely variable cylinder deactivation system, firing only the cylinders needed to deliver the performance the driver needs.
The current generation of cylinder deactivation technology, used in GM’s V-6 and V-8 small block engines, uses electrically controlled valve lifters to turn off half the cylinders in the V-8 and two cylinders in the V-6 engine. It offers up to a 5 percent fuel economy gain. DSF can run an engine on various combinations of even and odd cylinders as needed, adding about 10 percent more fuel economy, or as much 15 percent greater fuel economy than engines without cylinder cut-off technology.
DSF is being developed by Tula Technology, Inc. The company received funding from GM Ventures LLC in 2012 for the system. GM Ventures is run by Jon Lauckner, GM vice president of global r&d.
The company, formed by GM in June of 2010, works with private companies to develop new technologies. GM has investments with about 20 start-up companies.
“This technology holds the potential to improve fuel economy on select GM vehicles without degrading power capability when it’s required,” Lauckner, said in a statement. “This joint effort combines software expertise from Silicon Valley with powertrain expertise from General Motors.”
GM is not giving much in the way of technical details on DSF. It isn’t clear if the new system would replace the electrically controlled valve lifters or work in conjunction with them.Product applications
If DSF makes production, it would likely appear on the next generation small block V-6 and V-8 due out around 2017. GM would use the system in its trucks and SUVs and rear-wheel drive vehicles, such as the Chevrolet Corvette and Camaro.
GM plans to meet stringent fuel economy standards with a combination of advanced powertrain technologies and lightweight aluminum body panels on select vehicles.