Spark/spark-free combustion engine

摘要

Ordinary spark-ignition automobile engines can,under certain driving conditions,move into a spark-free operating mode that is more fuel-efficient.The mode-switching capability could appear in production models within a few years,improving fuel economy by several miles per gallon in millions of new cars each year.That could cut oil demand in the U.S.alone by a million barrels a day,said researchers at Massachusetts Institute of Technology.Currently,the U.S.consumes more than 21 million barrels of oil a day.