This work aims at developing a new cooling fan for vehicle engine. This fan can operate as a cooling fan at low vehicle speed. At high vehicle speed, however, the fan is rarely used as a cooling fan. Therefore the fan can be used as a wind turbine, which generates electric power. In the previous report we had confirmed the effect of S-Shaped blade profile on the wind turbine efficiency by CFD analysis and the experiments. The present paper reports the enhancement of wind turbine power by installing high solidity rotor on a vehicle. High solidity rotor can increase the wind turbine efficiency and receive more input power due to the increased rate of the rotor resistance to the total resistance through the cooling system, although the air flow rate through the system decreases. We confirmed by the estimation and the actual vehicle test that the high solidity rotor can regenerate more electric power than the original low solidity rotor.