The American Petroleum Institute (API) has updated the standard governing its Engine Oil Licensing and Certification System (EOLCS), which outlines how engine oil marketers certify gasoline and diesel engine oils to meet the organization’s performance requirements.

The 24th edition of API 1509 includes the latest engine oil performance standards, licensing requirements, and marketing guidelines for products carrying the API Engine Oil Quality Marks.

“API 1509 plays a crucial role in managing the API Engine Oil Licensing and Certification System, providing oil marketers with guidelines on licensing and proper display of the API Engine Oil Quality Marks for consumers,” said Bill O’Ryan, director of API’s Engine Oil Licensing and Certification System and diesel exhaust fluid programs. “The updated standard assures consumers that API-certified engine oils are the highest quality option for their vehicles.”

The standard describes the voluntary licensing program, explains how new engine oil performance standards are developed, and outlines aftermarket conformance and enforcement procedures intended to ensure products claiming to meet API standards continue to comply.

While the update applies to both gasoline and diesel engine oils, it has implications for heavy-duty fleets by incorporating the latest diesel engine oil performance specifications used throughout the commercial trucking industry.

API said its standards are developed through an American National Standards Institute-accredited process, supporting acceptance by state, federal and international regulators.