In this paper a literature review is made on the application of nanofluids as coolant in automobile radiators. The nanoparticles by virtue of their smaller size possess more surface area than the bulk material, which shall enable them to absorb and dissipate heat at a faster rate. Generally water and ethylene glycol are used as coolants in automobile radiators. Several investigators have used nanofluids consisting of nanosize particles of TiO2, Al2O3, SiO2, CuO, Fe2O3, etc., suspended in the coolant used in the radiator of automobiles. These investigators have observed that the application of nanofluids increases the cooling rate and shall pave way for reducing the weight and size of the radiator, there by contributing to smaller and efficient radiators.