NOx and soot emissions from internal combustion engines, and in particular compression ignition (diesel) engines, are reduced by varying fuel injection timing, fuel injection pressure, and injected fuel volume between low and greater engine loads. At low loads, fuel is injected during one or more low-pressure...http://www.google.de/patents/US7464690?utm_source=gb-gplus-sharePatent US7464690 - Adaptive engine injection for emissions reduction
