The world consumption of fuels is undoubtedly unstable causing world economic crisis so this factor has urged all nations especially the government and the academics to find another alternatives to replace the usage of petroleum. Thus, by using biodiesel as alternative, the problem could be tackled, therefore, an experimental investigation has been conducted on water cooled multi cylinder 45 KW automotive diesel engine widely used in transport sector of India, fuelled with the various blends of bio-diesel extracted from the waste cooking oil (Soybean). Engine performance is also evaluated using diesel fuel without any modification in a present engine. A single step batch transesterification process of waste cooking oil to obtain biodiesel fuel was studied in order to optimize the process variables such as catalyst concentration, reaction time and reaction temperature which affect the product yield during transesterification process. The variable that was fixed throughout the whole experiment was the molar ratio of methanol to raw oil (6:1).The important properties of waste cooking oil bio-diesel were also determined as per standards. Experiments were conducted using different blends of biodiesel and diesel such as B15, B25, B35 and B45 and its effect on brake power, specific fuel consumption, break thermal efficiency, mechanical efficiency and smoke density etc with respect to the load on the engine were reported. The results of experimental investigation were compared with that of pure diesel. The test results indicate that the B-15 blend of bio-diesel can act as alternative fuel.
