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API maintains a number of lubricant-related publications. Most deal with API’s Engine Oil Licensing and Certification System (EOLCS). Some of these publications may be purchased through the API Publications, Programs, and Services Catalog. Others are available on request from EOLCS (teameolcs@api.org).

API 1509, Engine Oil Licensing and Certification System, 17th Edition, Addendum 1 (October 2014 with Errata March 2015)

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 by clicking on the link below.

Base Oil Interchange (BOI) and Viscosity Grade Read-Across Guidelines are now available as downloadable pdf files. Click on the links below to download the most recent versions of both.

API 1525A - Addendum 1, Bulk Engine Oil Chain of Custody and Quality Documentation

API 1525A - Addendum 1 provides procedures for managing bulk engine oil chain of custody to ensure oil quality from the point of manufacture to installation in the end user’s engine.

Publication 1520, Directory of Licensees: API Engine Oil Licensing and Certification System

Assists consumers in selecting quality engine oils by identifying the companies licensed to display the API Engine Oil Quality Marks. This Licensee Directory is updated as often as several times a week and can only be accessed on-line.

Publication 1560, Lubricant Service Designations for Automotive Manual Transmissions, Manual Transaxles, and Axles, 8th Edition, April 2013

Publication 1560 describes API gear lubricant service designations and assists manufacturers and users of automotive equipment in the selection of transmission and axle lubricants for a variety of operating conditions.

Engine Oil Guide

This four-page laminated guide is designed to help consumers understand the API Engine Oil Quality Marks—the API Certification Mark "Starburst" and Service Symbol "Donut"—and the API Service Categories. A downloadable Engine Oil Guide shelf card is available in PDF format.

Guía de Lubricantes para Motores

Esta guía laminada ayuda a los consumidores entender el significado del Símbolo de Servicio y la Certificación de API. Pincha sobre file examinar una versión pdf. (Las características de la página se deben fijar al paisaje al imprimir.)

The Engine Oil guide is also available in Chinese. 机油指南 (Engine Oil Guide)

Shelf Cards are available in English, Spanish and Chinese and can be personalized with company logos. For information on personalizing the Shelf Cards, call (202) 682-8516. Individual copies of the cards are available free on request to API at eolcs@api.org or 1-202-682-8516. Multiple copies can be purchased by contacting API at the e-mail address or phone number above.