This paper describes the simultaneous reduction of nitrogen oxides (NOx) and smoke in a modern light-duty diesel engine under high exhaust gas recirculation (EGR) levels. Simultaneous reduction of NO x and smoke emissions was achieved using two different approaches. The first approach utilizes a medium level of EGR (O2 concentration = 15%), retarded injection timing and high injection pressure. The second approach utilizes a high level
EGR (O2 concentration = 13%), advanced injection timing and high injection pressure. The results showed the heat release rate of low temperature diesel combustion and the effects of a combustion control parameter incorporated in this combustion concept. The results also made clear the effects of the fuel injection parameters of a common rail injection system. Based on these results, this paper discusses the effects of combustion control parameters on low temperature combustion as well as emission characteristics.