The use of biodiesel reduces emissions like hydrocarbon (HC), carbon monoxide (CO), carbon dioxide (CO2), particulate matter (PM); but increases nitrogen oxide emissions. Additives inculcated in diesel and biodiesel has served as one of the means to decrease NOx emissions. An attempt is made to investigate the effect of the addition of ethanol and clove oil, to Pongamia biodiesel, on performance and emission characteristics. Pongamia biodiesel was extracted by transesterification using potassium hydroxide (KOH) as a catalyst. 5% Ethanol and 0.5 and 1 ml clove oil were added to the esters produced. B20 (20% biodiesel + 80% diesel), B20E5 (20% biodiesel + 75% diesel +5% ethanol), B20E5CL0.5 ( 20% biodiesel +75% diesel+5% ethanol +0.5 ml Clove oil) and B20E5CL1 (20% biodiesel + 75% diesel+5% ethanol +1 ml Clove oil) were analysed. The test was performed on a single-cylinder, four-stroke engine connected to an eddy current type dynamometer for loading. The addition of 1ml of antioxidant (clove oil) resulted in an increase in brake thermal efficiency by 8.9% and brake specific fuel consumption marginally by 1.53 %. At higher loads, the B20E5CL1 blend showed a 13% reduction in NOx emission. B20E5CL1 blend also resulted in a reduction in CO emission at higher loads. Ethanol addition to the biodiesel (B20E5 blend) resulted in the highest brake thermal efficiency but at the cost of NOx emissions. Blends with ethanol and clove oil reported good results at higher loads.