Particulate Emissions may obsolete Direct injection engines

Two relevant articles: Green Car Congress: Audi using supplementary port fuel injection to address particulates from gasoline direct injection

Chrysler V-6 Shines in Both Cars and Trucks | Vehicles & Technology content from WardsAuto

"While direct injection frequently is referred to as the wave of the future, the Chrysler Pentastar’s chief engineer says new particulate emissions standards will have auto makers shifting back to port injection..... “I know that several manufacturers are looking at adding port fuel injection to their DI engines for that reason,” he adds. Gorgas breaks down potential future improvements into three potential areas: frictional, thermodynamic and pumping. “Some people are running Atkinson Cycle-like engines with very late intake-valve closing along with variable-valve lift and/or MultiAir to reduce pumping losses,” he says.

“The thermal-management system can use heat generated by the engine to help in other areas of the vehicle to get things up to their optimum temperatures as quickly as possible. It's a process of adding all these different devices and looking at it from a full-vehicle systems approach, not just an engine approach.”