Globally, transportation is the second largest energy consuming sector after the industrial sector and is completely dependent on petroleum products and alternative technologies. So, fossil fuel consumption for energy requirement is a primary concern and can be addressed with the fuel consumption reduction technologies. Transportation sector is mainly using diesel engines because of production of high thermal efficiency and higher torque at lower RPM. Therefore, diesel consumption should be targeted for future energy security and this can be primarily controlled by the petroleum fuel substitution techniques for existing diesel engines. Some of the fuel, which includes biodiesel, alcohol-diesel emulsions and diesel water emulsions etc. Among which the diesel water emulsion (DWE) is found to be most suitable fuel due to reduction in particulate matter and NOx emission, besides that it also improves the brake thermal efficiency. But the major problem associated with emulsions is the ignition delay, since this is responsible for the power and torque loss. In this exhaustive study, first a comparative investigation is conducted between diesel and 10% emulsion; and in the consequent phases, performance and emission characteristics of 10% water diesel emulsion is evaluated at various injection angles on a single cylinder, water cooled diesel engine. In the comparative study for different injection angles, it is found that on advancing the injection angle the peak pressure is shifted towards TDC and because of that, torque is increased slightly. In the consequent phases of emission studies, a reduction in NOx emission was observed due to reduction in combustion chamber temperature by the use of emulsion. However, this pattern was not uniform at all loads. It was found that as the water concentration increases, the temperature inside the combustion chamber decreases which in turn leads to decrease in NOx formation.