Behr America’s Visco technology for engine-coolant pumps reduces power losses that affect fuel economy and promises savings of up to 1% for heavy-truck owners. The electronically controlled system varies coolant-pump speeds based on engine requirements and operating conditions. Visco technology hydraulically isolates engine input and minimizes power consumption under high-speed operation and light engine loads not requiring maximum flow rates. The pump's control logic is embedded in an engine-control module, while energy tied to a belt drive is transferred hydraulically to an impeller. The variable-speed Visco clutch operation allows for precise coolant flow rates, is designed for the life of the vehicle, and does not require maintenance. Visco-equipped coolant pumps are expected on up to 60,000 heavy-duty trucks within the next two years.