This study investigates the Glycine max (soybean oil) biodiesel with hydrogen along with MgO nanoadditives on compression ignition engines. A series of tests were conducted at various loading conditions in a water-cooled, single-cylinder, constant-speed engine. The biodiesel-blended soya oil was used as the primary fuel, and hydrogen was added at a constant volume of 25 LPM. Additionally, MgO nanoparticles were dispersed to the blends at concentrations of 50 ppm. In this study, it was found that the addition of hydrogen to the compression ignition (CI) engine resulted in an increase in combustion performance. In addition, hydrogen and oxygen molecules significantly reduced the exhaust gas temperature and brake-specific fuel consumption of biodiesel samples. An increase in nanoparticle concentration resulted in a reduction in emissions of pollutants such as CO2, CO, and HC. Inclusion of the hydrogen in the combustion chamber reduces the carbon content burned. Further, the availability of extra molecules in the MgO aids the fuel to reach higher combustion rates. At higher load conditions, biodiesel blends showed a slight decrease in NOx emissions. Overall, from the findings, it is clear that hydrogen addition and nanoparticles enhanced emission and combustion process, which is attributed due to the increase in hydrogen content in the fuel. © 2023 Elsevier B.V., All rights reserved.