Horton announces the introduction of its VMaster Ultra Fan Drives in anticipation of new emission regulations. Managed by the engine's electronic control unit for precision fan speed control, these directly controlled viscous fan drives are designed to cool higher-horsepower, hotter-running engines. VMaster Ultra Fan Drives are being road tested by OEMs and fleets on the new reduced-emission vehicles. The fan drive is equipped with an integral fan speed sensor to provide closed-loop control capabilities. VMaster Ultra's optimized magnetic design speeds up reaction time for better modulation and cooling.