More demand for fossil fuel and significant increase in the air pollution levels due to combustion of the fossil fuel provides an opportunity to discover some clean and environmental friendly fuels for the engines. The present work is focused on the optimization of engine operating parameters to result in the optimum increase in the efficiency of the engine running on polanga biodiesel blends. The fuel injection pressure, fuel injection timing, polanga based biodiesel blends, and engine load were considered as input parameters for the optimization of brake thermal efficiency (BTE), unburnt hydrocarbon (UHC), and NOx emission. Experiments were conducted as per the central composite rotating design (CCRD) matrix. The optimum combination of input parameters for maximum brake thermal efficiency and minimum exhaust emissions were found at fuel injection timing 15 bTDC, fuel injection pressure 196.36 bar, 40% biodiesel blend (B40) and 53% engine load. Experimental and optimized results at the prescribed optimum setting were compared and the error percentage were found within the limit of 5%. (C) 2018 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.