In this study, Pomolion Stearin wax oil biodiesel with zinc oxide additive was studied in a single-cylinder, stationary, air cooled and direct injection compression ignition engines as well as its effects on engine performance and exhaust emissions were studied. The Pomolion Stearin Wax oil Methyl Ester (PSWME) is mixed with the zinc oxide nanoparticles in the mass fractions of 50 ppm and 100 ppm with the aid of an ultrasonicator. The average diameter of the zinc oxide nanoparticles is less than 100nm. The properties such as flash point, kinematic viscosity, cetane number, cloud point, sulphated ash and calorific value of all blends were determined and compared with ASTM (D7467) standards. The experiments were conducted at a constant speed of 1500 rpm. The acquired data were studied for various parameters such as brake mean effective pressure (bmep), brake specific fuel consumption (BSFC), brake thermal efficiency (BTE), exhaust temperature and exhaust gases of Carbon monoxide (CO), hydro carbon (HC) and Nitrogen oxide (NOx) gases for 80% Diesel + 20% PSWME (B20), 80% Diesel + 20% PSWME + 50 ppm Zinc Oxide (D80B20ZnO50) and 80% Diesel + 20% PSWME + 100ppm Zinc Oxide (D80B20ZnO100) fuel blends at different loads, i.e., 0%, 25%, 50%, 75% and 100% were tested.