A radiator assembly in a vehicle comprises a first coolant tank; a second coolant tank spaced apart from the first coolant tank; a plurality of moveable blades; a linkage coupled to the plurality of blades; and an actuator coupled to the linkage to adjust positions of the blades. Each of the plurality of blades has a first end pivotally coupled to the first coolant tank, a second end pivotally coupled to the second coolant tank and has a hollow body portion extending between the first end and the second end, and each of the blades is fluidly communicated with the first and second coolant tanks to form a coolant passage.