The increasing demand for alternative fuels for diesel engines due to the depletion of petroleum reserves and concerns over global warming has led to the proposal of incorporating nanomaterials into pure diesel or diesel-ethanol blends. This study aims to compare the combustion characteristics and engine performance of different ethanol/diesel blends with Molybdenum-doped titanium dioxide nanoparticles. The study also evaluated the emissions produced by these blends, including emission gases and their potential impact on human health and the environment. The ethanol-diesel blend with 5% ethanol, denoted as E5, was used, and samples with nanomaterials were denoted as E5-1%Mo, E5-3%Mo, and E5-5%Mo for 1%, 3%, and 5% of Mo doped in the TiO₂ nanoparticles, respectively. The nanomaterials were added to the ethanol-diesel blends with a concentration of 50 mg/liter. The experiments were conducted using a GUNT CT 400.02 4-cylinder four-stroke diesel engine with 1,896 cc. The study found that the diesel engine's performance and emissions were significantly affected by the load and the specific nanomaterial used. The ideal blend of nanomaterial also varied depending on the load. E5 was the best choice between all ethanol-diesel blends. It shows increase in exhaust temperature, in cylinder pressure as well as reduction in CO emissions by 46.2% at full load. The E10 sample has the best reduction of NOx by 26.33% at full load. Addition of TiO₂-Mo nanoparticles significantly enhanced the brake thermal efficiency with E5-3% Mo sample showing the best performance. Also, the used nanomaterials reduce the CO emissions by 33.56% compared to the pure diesel but increases NOx emissions by 12.54%.