The API Engine Service Classification System provides a voluntary program to inform the consumer of the quality and performance of oils purchased. This publication describes the API Engine service Classification System and its application.
API PUBL 1509-1985 history
1996API PUBL 1509-1996 Engine Oil Licensing and Certification System (Fourteenth Edition; Addendum 1 December 1998; Technical Bulletin 4 July 6@ 1999)
1995API PUBL 1509-1995 Engine Oil Licensing and Certification System Thirteenth Edition
1993API PUBL 1509-1993 Engine Oil Licensing and Certification System (TWELFTH EDITION)
1988API PUBL 1509-1988 ENGINE SERVICE CLASSIFICATION SYSTEM AND GUIDE TO CRANKCASE OIL SELECTION (ELEVENTH EDITION)
1985API PUBL 1509-1985 Engine Service Classification System and Guide to Crankcase Oil Selection (Tenth Edition; ADDENDUM: July 1986)
1983API PUBL 1509-1983 Engine Service Classification System and Guide to Crankcase Oil Selection (Ninth Edition)
1980API PUBL 1509-1980 Engine Service Classification System and Guide to Crankcase Oil Selection (Eighth Edition)
1979API PUBL 1509-1979 Engine Service Classifications and Guide to Crankcase Oil Selection (SEVENTH EDITION)
1972API PUBL 1509-1972 Engine Service Classifications and Guide to Crankcase Oil Selection (Sixth Edition)
1969API PUBL 1509-1969 CLASSIFICATION OF INTERNAL COMBUSTION ENGINE SERVICE to Guide the Choice of Crankcase Oils (Fourth Edition)
1965API PUBL 1509-1965 CLASSIFICATION OF INTERNAL COMBUSTION ENGINE SERVICE to Guide the Choice of Crankcase Oils (Third Edition)
1956API PUBL 1509-1956 INTERNAL COMBUSTION ENGINE SERVICE GUIDE THE CHOICE OF CRANKCASE OILS