The American Petroleum Institute (API) announced progress in the development of its new Proposed Category 12 (PC-12) heavy-duty engine oil specification, clearing several key steps toward formal adoption.

The API Lubricants Standards Group (LSG) has approved three actions that will now advance to a 30-day electronic ballot for inclusion in API 1509, according to a news release.

Those actions include acceptance of the PC-12 technical requirements as outlined in the ASTM D4485 ballot, with minor editorial updates; acceptance of the PC-12 user language describing the new API CL-4 and API FB-4 service categories; and approval of Jan. 1, 2027, as the first license date for both categories.

The electronic ballot process will allow API LSG members to review the proposals and provide feedback before final adoption.

The approvals follow coordinated technical reviews across multiple industry groups. During recent ASTM D02 meetings, the diesel engine oil advisory panel and the PC-12 new category development team aligned on updates to the ASTM D4485 standard. Those recommendations were subsequently forwarded to the API LSG, which confirmed the path forward for PC-12 development.

To support the transition to the new categories, the API licensee portal will open several months ahead of the Jan. 1, 2027, first license date. The early-access period will allow licensees to enter API CL-4 and API FB-4 products in advance. API said it will notify licensees once early entry becomes available.

The approved actions mark a milestone in finalizing the PC-12 specification and preparing the heavy-duty engine oil industry for next-generation performance standards.