In the early 1960's the U.S. Military began to gradually phase-out piston engined aircraft from it's inventory in favor of gas turbine powered aircraft. The emphasis of the aviation industry on the development of the new gas turbine engines and their attendant new synthetic lubricants resulted in the rapid decline of new oil development for aviation piston engines. As a result of this change in focus by the military and commercial engine builders, the maintenance of the MIL-L-6082 and MIL-L-22851 specifications also diminished. After years of decline, commercial interest in these specification products again developed. This paper is an attempt to document the rational used in modernizing these two specifications.