Horton's Arctis Two-Speed Fan Drives provide a better, more efficient engine cooling for medium duty trucks, buses, severe service vehicles, rear engine cement mixers and other on- and off-highway equipment with little to no ram air. The Arctis line provides the highest torque available from Horton - 2,700 inch-pounds. In most conditions, the fan drive is powered by eddy current, turning the fan at a lower speed, reducing operating noise and increasing available horsepower for auxiliary systems. When the vehicle needs more cooling, the fan drive springs actuate to run the fan at full input speed. Because the eddy current mode provides sufficient cooling in most operating conditions, full-speed fan operation is reduced by 85 percent which improves fuel economy. Fewer fan engagement cycles also improve fan drive, belt and tensioner reliability while minimizing radiator abrasion from dust and debris.