The use of water-in-diesel (W/D) emulsion as a diesel substitute has imposed significant interest due to its benefits to engine performance and exhaust emissions. However, the development on emulsification technology especially without using surfactant is still not widely known. Therefore, in this study, a study into the application of non-surfactant W/D emulsion has been done with the objective to analyze the potential of non-surfactant W/D emulsion made from low grade diesel as a substitute for higher grade diesel. This study was conducted using light-duty diesel vehicle, a 1 ton truck tested in a chassis dynamometer. A variety of test fuels was used, comprises of Diesel Euro 5 (DE5), Diesel Euro 2 (DE2) and emulsion made from Diesel Euro 2 (EDE2). EDE2 was produced real time just before it is injected into the diesel engine, with water percentage of 6.5% and no additional surfactant. The testing was executed on a chassis dynamometer in accordance to the West Virginia ( VVVU) 5 Peak-Cycle standard. Among the data collected are fuel consumption, exhaust temperature, gas emissions (NOx, CO and CO2) and smoke number. The results show that the EDE2 improved the engine fuel consumption by 7.39% compared to DE5. As for exhaust emissions, EDE2 produced slightly higher NO. and CO compared to DE5. However, CO2 and smoke of EDE2 were found to be lower. For that reason, with some adjustments, non surfactant W/D emulsion fuel made from low grade diesel has a potential to be applied in road transport with some adjustment in order to replace the high grade diesel. (C) 2016 Elsevier Ltd. All rights reserved.