A number of attempts are being made to conserve fossil fuels. The diesel engine, because of its better fuel economy and lower maintenance cost has become the dominant in the field of transportation, agricultural and industrial sectors. Simultaneous reduction of emissions of both oxides of nitrogen (NOx) and particulate matter from diesel engine is very difficult. This can be achieved by using water diesel emulsion, increased injector opening pressure and oxygenated fuel additive. Ethyl acetate was used as an additive as well as oxygenated compound to keep the blends in homogeneous, stable state and to promote combustion due to the inherent oxygen in the fuel molecule. The effects of water diesel emulsion, increasing injector opening pressure and ethyl acetate addition on engine's fuel economy and emissions were studied on a single-cylinder DI diesel engine. The experimental results show that percentage of water in emulsion can be enhanced by increasing the injection pressure and use of oxygenated fuel. The engine emissions of CO, HC, smoke density and NOx were reduced when injector opening pressure increased and ethyl acetate was added in diesel oil. Use of the emulsions also resulted in decrease in BSEC.