In this present work, investigations are carried out to study the performance and emission characteristics of adding diethyl ether as an oxygenated additive with the selected ratio of 70D:30E. For this experiment, a single-cylinder, four-stroke, water-cooled diesel engine is used. Initially, the engine is run with diesel no. 2 fuel and the readings are recorded. Then, the engine is run with the emulsified fuel ratio of 70D:30E by a volume basis and the readings are taken in to an account. Finally, along with the emulsified fuel 70D:30E, the oxygenated additive diethyl ether is added on a 10% by volume basis and the readings are also being observed. On the basis of the test results, the oxygenated additive diethyl ether added emulsified fuel shows increase in brake thermal efficiency and decrease in specific fuel consumption, smoke density, particulate matter, and oxides of nitrogen comparted to the diesel fuel no. 2 and the emulsified fuel.