Xenia car has many support systems, one of which is engine cooling system. Cooling system (cooling system) is a series to overcome the occurrence of overheating on the machine for the machine can work optimally. Therefore, in this study, it is necessary to study the variation of cooling fluid type on the cooling system to the radiator capacity which is to know the effectiveness of Xenia car radiator performance. This research is using experimental method. This research is intended to find out the influence of different types of cooling fluid to the capacity of Daihatsu Xenia engine radiator trainer. The independent variable used is the type of cooling fluid, the control variable is the fluid mass flow rate, the inlet fluid temperature, and the discharge (LPM), and the dependent variable is the radiator capacity. Variations of the type of cooling fluid used are water, prestone coolant radiator, O.B.C premix radiator coolant and mixture of two types of prestone fluid coolant and O.B.C premix radiator coolant. In the testing process is done gradually and record the test results. This research uses descriptive analysis method.. The results of this study show that the lowest rate of heat transfer (radiator capacity) is achieved in the type of prestone fluid at temperature 90 (C) at 25188.376 Watt, while the highest heat transfer rate is achieved in the OBC and prestone mixed fluid types (50%: 50%) at temperature 90 (C) that is equal to 41577,526 Watt.