Radiators are heat exchangers used to transfer thermal energy from one medium to another for the purpose of cooling and heating. The majority of radiators are designed to service in four wheeler and heavy duty vehicles. The radiator is always a origin of heat to its environment, although this may be for either the function for cooling the fluid or of heating this environment, or coolant supplied to it, as for engine cooling. In existing plain fins type radiator are commonly used, which are usually set up in a cross flow arrangement made up of aluminum and copper alloy. Powerful fan and water pump is accompanied in this to greatly improve heat dissipation rate. The addition of fins is one of the way to improve and increase the rate of radiator cooling. This method follow the principle of increasing contact surface. Contact surface can also be increased by varying fin geometrical structure. In this project simple modification has been carried out in the existing fin geometry with a view to improve its heat dissipated rate. Also comparison of conventional coolant withNanofluids has been carried out by using PTC Creo 3.0 and analysis is carried out by using Ansys v16. The result are compared and optimum fin design is concluded.