What is the direction of a radiator fan, suck or blow, in or out?
Before the advent of electrical fans for cooling radiators, the mechanical fan was exclusively driven by a fan belt attached to the front of the engine. This forced the fan to "suck" air through the radiator. This arrangement also looked neater, with the moving parts of the engine hidden from sight. There is an option now for some automobiles, to have the electric fan in the same location, behind the radiator, or in front of the radiator. Once the automobile reaches about 25 mph, the fan is superfluous and in many cars, the clutch fan disengages the fan blade to reduce fuel consumption.