The next generation of diesel engines is likely to utilise higher injection pressures, possibly over 2000bar, and high exhaust gas recirculation (EGR) concentration. The complex interactions between fuel injection pressure, piston bowl geometry and EGR concentrations have a significant effect on fuel consumption and pollutant emissions. Precise mechanisms remain uncertain, thus inhibiting the design of high-efficiency clean powertrains. The objective of the project is to investigate these mechanisms using state-of-the-art facilities, including optical research engines, ultra-high-speed video and laser diagnostics.