This study investigated the change adhere by adding oxide of cerium nanoparticles to a 10% biodiesel blend (B10) on the engine performance and its emissions. The results are been compared with those from conventional diesel and standard B10 fuel. The two nanoparticle concentrations which are ben used are of 50 ppm and 100 ppm, were tested. The experimental procedure began with mixing cerium oxide nanoparticles into the B10 blend, followed by detailed testing using an engine or dynamometer setup to measure key parameters. The primary focus of the study was to get the performance metrics like Brake Thermal Efficiency (BTE) and consumption of fuel, along with a thorough analysis of emissions, including oxides of nitrogen (NOx), hydrocarbons (HC), and oxides of carbon (CO2 and CO). By comparing these parameters across pure diesel, B10, and cerium oxide-enhanced B10 fuels, the study assessed the impact of cerium oxide nanoparticles on engine performance and emissions. Results showed significant improvements with the alteration of oxide of cerium, including a notable 16.5% increase in BTE compared to B10, indicating better energy conversion efficiency. Additionally, there was a substantial reduction in NOx emissions by approximately 14.5% and a 29% decrease in CO emissions compared to the B10 blend. These findings suggest that incorporating cerium oxide nanoparticles into blends can significantly enhance efficiency and reduce emissions, highlighting potential of nanotechnology in developing environment friendly and sustainable fuel solutions.