This study assessed the impact of hydrogen and TiO2 nanoparticles in soybean biodiesel (B15) on CRDI engine performance. A hydrogen flow of 10 L/min and 75 ppm TiO2 nanoparticles were used. Compared to diesel, the biodiesel blend improved performance, combustion, and emissions. Brake fuel consumption decreased by 16.12% and brake thermal efficiency increased by 3.53% at 80% load. CO, HC, and smoke were reduced by 30%, 50%, and 42%, respectively, while NOx increased by 12.15%. The combination also improved in-cylinder pressure by 9% and HRR by 7%, demonstrating potential for hydrogen-enriched, nanoparticle-incorporated biodiesel in engines.