API American Petroleum Institute

For more than 75 years, API has led the development of petroleum and petrochemical equipment and operating standards. These represent the industry’s collective wisdom on everything from drill bits to environmental protection and embrace proven, sound engineering and operating practices and safe, interchangeable equipment and materials. API maintains more than 500 standards and recommended practices. On this site we introduce API's most important lubricant standards.

API Engine Oil Service Category Charts

API Gear Oil Specifications

API Two-Cycle Service Classifications