The research is conducted on emulsified fuel applied to engine YC6J190 without any modification of the engine. In this experiment, the contrast of the fuel consumption and the emissions is studied with having water or not. From the results, it can be concluded that the emulsified fuel can reduce the NOx and smoke emissions greatly at the same time, but the fuel consumption is different in different conditions. The emulsified fuel with 20% water is most suitable for this type of engine regarding fuel consumption and emissions. Then dynamic characteristics is tested using the emulsified fuel with 20% water to find that the decline in power and torque output is not apparent. At the end, we conclude that emulsion containing 20% of water would replace diesel as for this type of engine.