Significant Considerations in Selecting Base Stocks for Automatic Transmission Fluids

The results of numerous laboratory bench tests and over-the-road field tests conducted on fluids blended with base stocks of varying physical properties are compared.

The effects of using oils derived from solvent-refining versus those manufactured from a hydrotreating process are examined.

Other areas investigated include comparisons of high vs. low VI; light vs. medium grade neutrals; and additive response to these differing base s tocks.

Although high viscosity index (HVI), hydro treated, medium grade neutrals generally gave superior results in the tests performed, it was determined ATF's blended with light grade hydrotreated neutrals of low viscosity index (LVI) also showed promising results when evaluated against standard industry tests.