As the load shifts to the medium load, the soot emissions for all fuels are quite low when the EGR is below 20%, while when the EGR rate is increased up to 20%, all fuels exhibit a significant rising trend in soot emissions and the diesel/PODE blends show great potential to reduce the soot emission compared to diesel. At high load, due to the low excess air ratio, the presence of oxygen in PODE blends results in more remarkable reduction in soot emission compared to diesel. It is seen that when the EGR rate is higher than 12%, the soot emission of diesel dramatically increases while the soot emission of diesel/PODE blends can still be maintained at very low level.