Synergistic effect of gasoline-DIPE blends with Mn3O4-NiO binary nanocomposites on MPFI engine combustion, performance and emissions

• The study investigates gasoline-DIPE enriched with Mn 3 O 4 -NiO nanocomposite blends for gasoline engines. • The D20MN100 blend showed the maximum brake thermal efficiency of 33.5%, higher by 23.3% over gasoline. • The peak cylinder pressure was found to be 33.39 bar for D20MN100, which increased about 18 % over gasoline. • CO emissions were reduced by up to 29 %, amounting to 0.305 % at 3000 rpm. • The combustion stability was improved: the COV IMEP values remained below 4% for all engine speeds. This study investigates the combined effect of di-isopropyl ether and Mn 3 O 4 -NiO nanocomposites on the performance, combustion and emission characteristics of a gasoline injection engine. Gasoline was blended with 10 % and 20 % DIPE by vol, and Mn 3 O 4 -NiO nanocomposites were incorporated at 50 and 100 ppm concentrations. The synthesized nanocomposites possessed phase purity, polycrystalline structure and particle sizes of 50–100 nm. Among the tested fuels, the blend containing 20 % DIPE and 100 ppm nanocomposite delivered the highest brake thermal efficiency of 33.5 % and the lowest specific fuel consumption of 0.305 kg/kWh, corresponding to improvements of 20 % and 19.44 % compared with gasoline. Peak cylinder pressure increased by 18 %, while unburned hydrocarbon and carbon monoxide emissions reduced by up to 47.37 % and 17.14 %, respectively. A slight rise in exhaust gas temperature was observed; however, nitrogen oxide emissions decreased by nearly 29 % lower than the D20 blend. This result highlights the potential of the DIPE-Mn 3 O 4 -NiO combination to improve combustion and emission characteristics in gasoline engines.