This paper describes the procedure by which candidate lubricants have been selected by the General Electric Co. and are being evaluated for the GE4 engine. The GE4 will use the same fluid in both the lubrication system and the hydraulic system, but systems are physically separate. Consequently, lubricants selected must also be capable of meeting several additional engine hydraulic fluid requirements. After accumulation of physical property and bench test data, a vigorous component test program is conducted to verify that oils selected meet all engine requirements. Industry-funded efforts to formulate advanced Type 2 lubricants for the GE4 will undoubtedly result in a general advance in lubricant performance for all aircraft turbine engines.