The NO emission for the diesel operation varies from 4.9 g/kW h to 2.82 g/kW h from no load to full load respectively, while the NO emission varies from 4.3 g/kW h to 1.2 g/kW h from no load to full load respectively for the 40LFPO operation. The reason for lower NO emission in the case of 40LFPO operation is the lower heat release rate in the premixed combustion phase.