scope:

This publication describes the API Engine Oil Licensing and Certification System (EOLCS), a voluntary licensing and certification program designed to define, certify, and monitor engine oil performance deemed necessary for satisfactory equipment life and performance by vehicle and engine manu- facturers. Engine oil marketers that meet EOLCS require- ments may be licensed to display two Marks, the API Service Symbol and the API Certification Mark.

Sections 2 through 6 of this publication define the current API engine oil service categories and explain the EOLCS licensing requirements, the API Marks and their use, and the EOLCS Aftermarket Audit Program. Appendices A through Q provide a brief history of engine oil classifications, describe methods for developing new engine oil performance requirements, and explain the interaction and roles of the vari- ous independent organizations that are part of the API EOLCS.