Alc. emulsions of TiO2, TiO2-CuO and TiO2-Pt nanoparticies were added to com. motor gasoline used in a motor vehicle of old generation to decrease the NOx, CO, particular matter and polyarom. hydrocarbons emissions. The results were compared with those for pure gasoline and liquefied natural gas (LPG). A substantial decrease of the emissions (51%, 46%, 44% and 71%, resp.) was obsd. The highest decrease of the emissions was hower evidenced when gasoline was replaced with LPG (74%, 64%, 72% and 92%, resp.).