Responding to signals from the engine control module thousands of times per minute, Cool Logic fan drives electronically vary fan speed to provide consistent, precise temperature control that automatically adjusts to load and road grades. The highly reliable and responsive wet-friction clutch design reduces engine drag, delivering more horsepower and greater fuel economy compared with traditional on/off or two-speed clutch systems. Its actuation logic system delivers quiet operation to increase cabin comfort and reduce driver fatigue. In addition to fuel savings, Cool Logic fan drives extend the life of the entire cooling system, including the radiator and charge air cooler, and decrease wear on serpentine belt components.