机油许可和认证系统（第十七版

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 manufacturers. Engine oil marketers that meet EOLCS requirements may be licensed to display three Marks, the API Service Symbol “Donut” and the API Certification Marks “Shield” or “Starburst” (as applicable).