API 1509 Documents

API 1509 describes the voluntary API Engine Oil Licensing and Certification System (EOLCS) and explains to marketers how different API marks are licensed and displayed for the consumer. The current edition of API 1509 is now available and can be downloaded in pdf format. 

Downloads

API 1509, Engine Oil Licensing and Certification System, 18th Edition, June 2019

File Size: 1.6 MB

Current complete edition

API 1509 Annex E-API Base Oil Interchangeability Guidelines for Passenger Car Motor Oils and Diesel Engine Oils (April 2019) (Revised May 2019)

File Size: .6 MB

New items are shown in red and deleted items in strikeout

API 1509 Annex F-API Guidelines for SAE Viscosity-Grade Engine Testing (April 2019) (Revised May 2019)

File Size: .6 MB

New items are shown in red and deleted items in strikeout