Marketers of engine oil must obtain a license from API to use the API Engine Oil Quality Marks: the API Service Symbol "Donut" and Certification Mark "Starburst." The use of the API Marks is a marketer's warranty that its licensed oils comply with the requirements set forth in API 1509 and API's Application for Licensure. The license application requires the applicant to certify that its oils meet Engine Oil Licensing and Certification System (EOLCS) requirements.
You can download API's Application for Licensure using the links below. Please review the application instructions before completing any of the application. New applicants must complete Parts A through D and Part Q (Part E is optional). All forms are available in writable Adobe PDF format.