In this research, a novel composite nanomaterial is synthesized and blended with gasoline and gasoline-bioethanol in different operational conditions of the engine. The investigated engine is EF7 spark-ignited (SI) that is operated in 25%, 50%, 75%, and 100% under λ = 0.7 and λ = 1.0 at 1400 rpm and 2800 engine speeds. The Ag/Nb co-doped TiO2 (TNA) is emulsified and homogenized with base gasoline and 80% gasoline-20% bioethanol. The results of emission and engine performance are compared with baseline gasoline. The results allow comparing the effect of composite nanoparticle on customary gasoline and blended gasoline-bioethanol at ideal stoichiometric and rich combustion condition. The results indicate that the gasoline-nano application is economic at lower loads (26.76% reduction in BSFC), whereas the gasoline-bioethanol-nano blend at 100% load is the best choice with up to 32.87% save in fuel consumption. Further, the proposed fuel structure with nano addition can decrease the emissions of CO, UHC, NOx, and CO2, while this decrease is more noticeable when the engine is not working ideally at λ = 0.7.
