The Water Diesel Emulsion (WiDE) fuel shows nepotism in terms of environmental and economical aspects. In the present investigation, WiDE is used as fuel for the diesel engine. Here, WiDE was prepared with various water percentages in the range of 0 to 15 using the non ionic surfactant with a HLB value of 6.31. The WiDE was prepared by using ultrasonic probe Sonicator and the mean diameter of water droplet was measured by using the dynolite microscope. The investigation was run on a diesel engine with WiDE as fuel, for finding the effect of performance, emission, and combustion characteristics. The engine was operated at a compression ratio of 17.5 with variable loads from 0 to 100% with an increment of 25% load. From the obtained results, it shows that emulsion fuels show less NOX emission when compared with the pure diesel. The amount of water concentration shows the greater effect on NOX emissions. From the obtained results, WiDE 10 shows greater break thermal efficiency due to micro explosion phenomenon and the WiDE 15 shows higher cylinder pressure. But the emulsion fuel produced higher HC and CO2 emissions when compared with the diesel. © TJPRC Pvt. Ltd.