Air BP 2389 Turbo Oil (Formerly Exxon 2389 Turbine Engine Oil) is a three-centistoke (cSt) grade, is an advanced turbine lubricant for military engine use and commercial and corporate aircraft accessory applications. It is a blend of synthetic basestocks and advanced-technology additives. ETO 2389 is qualified against U.S. military specification MIL-L-7808K, Grade 3. It is specially formulated to combine the thermal and oxidation stability properties of a 5-cSt polyol ester commercial oil with the low-temperature fluidity of a 3-cSt oil. In addition, it has gear-load-carrying ability equal to or better than that of other approved MIL-L-7808K or MIL-PRF-7808L Grade 3 oils.