report no. 9/10
Two single-cylinder diesel engines were optimised for advanced combustionperformance by means of practical and cumulative hardware enhancements thatare likely to be used to meet Euro 6 emissions limits and beyond. Theseenhancements included high fuel injection pressures, high exhaust gas recirculationlevels and charge cooling, increased in-cylinder swirl, and a fixed combustionphasing. These enhancements achieved low engine-out emissions of NOx andparticulate matter emissions with engine efficiencies equivalent to today.s dieselengines. These combustion conditions approach those of Homogeneous ChargeCompression Ignition, especially at the lower part-load operating points. Four fuels exhibiting a range of ignition quality, volatility, and aromatics contentswere used to evaluate the performance of these hardware enhancements onengine-out emissions, performance, and noise levels.