In this study, waste cooking oil biodiesel was mixed with titanium dioxide (TiO2), a metal-based nano particle, and n-butanol (C4H9OH) along with euro diesel to examine their effects on diesel engines. Various ratio of fuel blends were prepared with TiO2 nano particles-diesel-biodiesel and n-butanol. The tests fuels were euro diesel (D100), biodiesel (B100), B20, B20+ TiO2, B20But10 and B20But10+ TiO2, respectively. Thermo-physical properties such as density, pour point, cloud point, cold filter clogging point, flash point and kinematic viscosity of all test fuels were determined followed by investigating engine performance parameters such as torque, power, fuel consumption and etc. Combustion analysis was also investigated. In addition, the effects on emissions such as CO, CO2, HC, NO and smoke opacity were also carried out.