Variable Speed Water Pump
Traditional water pumps constantly circulate coolant through a series of passages, cooling the engine components from the extreme heat generated through combustion and rejecting extra heat as the coolant passes through the radiator.

New variable speed water pumps do not operate at full power all the time and therefore reduce the load on the engine. Managing pump speed through controls without compromising the cooling necessary reduces the overall horsepower required to drive the water pump.
It is important to note that water pumps typically consume 1.1–1.8% of the truck’s fuel to perform their function, so any fuel economy gains from new technology will be modest.
Benefits
Fuel Savings (If Coupled with Higher Capacity and Higher Voltage Electrical System)
Challenges
Not Available for Most Vehicles as of March 2017
Increased Complexity of Electrical System
Higher Electrical System Voltage and Power Output Required
Reliability Issues
Increased Maintenance Costs
To learn more, download the Variable Engine-Driven Accessories Confidence Report.