The i-DSI (Dual and Sequential Ignition) four-cylinder engine is a technological marvel, with two spark plugs per cylinder to promote complete combustion, boost fuel efficiency and cut emissions. The engine burns clean enough to earn it an Ultra Low Emissions Vehicle (ULEV) rating. Additionally, the engine debuts a new "cylinder de-activation system" that cuts fuel flow to three combustion chambers during deceleration. This reduces friction by 30 percent, allowing the batteries to capture energy that would otherwise be lost.

Originally posted by Red Nj-s
It is probably going to be somthing included on every engine soon, sorta like how variable cam timing is on most every engine.