© 2022, Akadémiai Kiadó, Budapest, Hungary.Experimental study is implemented in order to study the heat transfer and flow characteristics of an actual heavy vehicle radiator using nanofluid. Deionized water mixed with anatase TiO2 nanoparticles, called nanofluid, is utilized in a heavy vehicle radiator. By preparing nanofluid for different volume concentrations of TiO2 nanoparticles (0.025, 0.05, 0.1 and 0.2%), experiments are carried out for various inlet temperatures (40, 50, 60, 70 and 80 °C) and volume flow rates (5, 8 and 11 LPM) at constant air velocity. Results show that heat transfer rate, heat transfer coefficient and Nusselt number have their highest values at 0.05% volume concentration, 80 °C inlet temperature and 11 LPM volume flow rate. Moreover, the values of heat transfer rate, heat transfer coefficient and Nusselt number are 2549.12 W, 858.62 W m−2·K−1, and 70.33 respectively, for the given case. The maximum enhancement in heat transfer rate, heat transfer coefficient and Nusselt number is observed as 22.2, 48.2 and 48.1%, respectively, compared to pure water. Maximum pressure drop, about 2.7% in comparison with pure water, is obtained at 0.2% concentration at 40 °C inlet temperature and 11 LPM volume flow rate. In order to obtain information about the overall characteristic of the system, the performance coefficient is calculated, and the results show that the performance coefficient is above unity in the volume concentration range of 0.025–0.05% at each inlet temperature and flow rate used in this study.