This specification covers the requirements for two grades of aircraft turbine engine lubricating oil.

The lubricating oil will be furnished in the following grades, as specified:

                        Grade              NATO Symbol

                          3                   0-148
                          4                   0-163

Grade 3 is normally used in most applications and will be supplied when requisitioned, unless otherwise specified.

Grade 4 should be specified when higher viscosity or greater thermal stability is needed. Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of use in improving this document should be addressed to: ASC/ENSI, 2530 Loop Road W, Wright-Patterson AFB OH 45433-7101, by using the self-addressed Standardization Document Improvement Proposal (DD Form 1426) appearing at the end of this document, or by letter.