API Approves Category 12 Heavy-Duty Engine Oil Specification for 2027

The American Petroleum Institute has announced the formal approval of the API Proposed Category 12 (PC-12) heavy-duty engine oil specification in a recent press release.

The new specifications will be incorporated into API 1509, the Engine Oil Licensing and Certification System document, and will make API Service Category CL-4 and API FB-4 “Donut” certification marks now available.

Oil marketers can begin finalizing formulations and preparing product packaging to meet the new specifications ahead of the first licensing date of Jan. 1, 2027. To support industry readiness, the API licensee portal will open on June 1, 2026. This early-access period will allow licensees to proactively enter new API CL-4 and API FB-4 products into the system.

“To support the next generation of heavy-duty engine technology and emissions standards, PC-12 establishes a strong technical foundation for performance, durability and environmental protection,” said Bill O’Ryan, director-EOLCS/DEF with API. “Making the CL-4 and FB-4 service symbols available now allows oil marketers to prepare for a smooth transition as we approach the 2027 model year.”