This study investigated how adding nanoparticles to cocklebur biodiesel affected a 4-stroke compression ignition (CI) engine. The biodiesel was mixed with titanium oxide nanoparticles at concentrations of 4 ppm in each blend. Engine performance characteristics were examined including consumed gas heat, brake thermal efficiency (BTE), and brake specific fuel consumption (BSFC). The tests were conducted under a variety of loads and speeds, and the outcomes were compared to those from tests using only pure diesel and only pure biodiesel. According to the findings, adding nanoparticles to the biodiesel enhanced engine performance, with the highest gains being shown at B36F4 content. At 75 % and 100 % load, the BSFC was reduced by 6.8 % and 7.6 %, respectively. When compared to pure biodiesel, the brake thermal efficiency increased by 6.7 % and 8.8 %. The temperature of the exhaust gas decreased as the concentration of nanoparticles increased. The performance of the 4-stroke CI engine was improved when nanoparticles were added to cocklebur biodiesel making it a competitive alternative to traditional diesel fuel.