Acronym for Spark Ignition Direct injection
It's the gasoline form of direct injection originally used only on diesel engines, now being used on some gasoline engines. Improves efficiency and power output.
Fuel injectors used in direct injection systems are more expensive than standard fuel injectors due to requiring more durable materials to withstand higher temperatures as the fuel injector is placed right into the combustion chamber.
This new SIDI engine sure is powerful, and the fuel economy ain't to bad either.