http://www.alu.army.mil/alog/issues/MarApr09/fuel_lubricant.html An excerpt... by Maurice E. Le Pera The author takes a historical look at the Army’s fuel and lubricant program and its effect on commercial lubricants. 'Synthetic-based engine oils were introduced in 1967 for all Army vehicles and equipment operating in Alaska using the Aberdeen Proving Ground Purchased Description Number 1 that later was converted into MIL–L–46167, commonly referred to as Arctic Engine Oil (OEA). This engine oil was essentially SAE 0W–20, which was quickly adopted by commercial operators building the Alaska pipeline system during the 1970s. Because of the successful performance of OEA in a variety of engine and powertrain systems, the Army subsequently field-tested this oil at several locations in Army tactical and combat vehicles and equipment to assess its applicability in moderate-to-hot temperatures. These tests were conducted at Fort Carson, Colorado; Fort Lewis, Washington; and Fort Bliss, Texas. In each case, OEA performance was satisfactory and no adverse effects were observed even while operating in the high-temperature environments. Although the Army did not pursue a fleet-wide conversion at that time, the successful performance of OEA both in different engine and powertrain systems and in various operating environments demonstrated its feasibility. This success attracted many commercial fleet operators to consider, and later adopt, synthetic-based engine oils.'