Development of the Fuel Saving Low Viscosity ATF

The limits and issues of reducing the viscosity of ATF were studied. The threshold for viscosity reduction at high temperature after shearing was determined through the data from field tests. Base oils and viscosity index improvers were selected to reduce the viscosity at normal temperature as low as possible, maintain the viscosity at high temperature after shearing. This experimental ATF was evaluated on several properties. However, this ATF had problems with the durability of friction materials and bearing fatigue life. Therefore, base oil's viscosity and the type of base oils were optimized to improve these problems. The developed low viscosity ATF showed same performance as conventional viscosity ATFs.