Abstract: A shroud for a vehicle engine cooling fan mounted to a generally rectangular radiator that has fixed air guide vanes in strategic areas of the shroud outside of the periphery of the fan blades to direct and channel streams of peripheral air flowing through the corners of the radiator into these areas inward and in a swirling pattern into the fan blades and more particularly in a generally smooth and circuitous path counter to the direction of rotation of the fan and directly onto the pumping surfaces of the fan blades. This effectively feeds additional air into the fan and preloads the blades so that air pumping efficiency is resultantly improved and more air is moved through the radiator for improved heat exchange.