Influence of Cetane Number on Euro III Engine Emissions

In order to evaluate the influence of diesel ignition quality - represented by its cetane number (CN) - on EURO III engines emissions, a matrix of fuels with cetane number ranging from 42 to 48 has been elaborated. In their formulation, an effort was made to keep the main properties, such as sulphur content, density and distillation (T90), within a narrow variation range, as they are known to influence emissions. Two Brazilian EURO III technology engines were used, one with a Common Rail injection system and, the other with a Unit Pump System (UPS). The following results are shown in this paper: CO, HC, NOx, CO₂ and particulate matter emissions, Bosch smoke and specific fuel consumption.