12-11-2014, 10:36 AM
Abstracts: Exhaust-gas recirculation returns some of the exhaust gases to the intake system, limiting the fresh-air intake and lowering the engine's combustion temperature to reduce NOx output. Increasing the EGR volume lowers NOx production to a point, but excessive EGR volume causes incomplete combustion, raising the particulate levels. Achieving the opposing goals of lower NOx production and lower particulate levels requires carefully tuned EGR levels .