Development of the Army's new Arctic Engine Oil (OEA) Specification MIL-L-46167 required numerous laboratory and field engine evaluations as well as large scale laboratory and field testing of these new lubricants in military hydraulic and power transmission fluid systems (HPTF). An earlier SAE paper emphasized the engine performance aspects of these synthetic oils, and now the current paper points up and emphasizes the significant performance areas in military HPTF systems. The new oils function well as year-round lubricants in Army HPTF systems including: automatic and power-shift transmissions, power steering units, hydraulic winches, pumps, and mechanical and construction equipment hydraulic systems. It appears that the new synthetic arctic engine oils have significant potential military applications in HPTF systems outside arctic regions as well as inside the arctic. Problem areas are discussed and a recommendation is advanced for the development of a truly “universal” HPTF.