API approves new updates for PC-12 specification

The API has made progress in developing the new API Proposed Category 12 (PC-12) heavy-duty engine oil specification, with the licensee portal to open several months before January 2027.

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American Petroleum Institute (API)

Jan. 9, 2026

2 min read

The American Petroleum Institute (API) has approved three new actions for review on the API Proposed Category 12 (PC-12) heavy-duty engine oil specification. Specifically, these three elements will now be voted on for inclusion in API 1509, the API Engine Oil Licensing and Certification System.

The 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, which provides a high-level description of the API CL-4 and API FB-4 categories.
Acceptance of January 1, 2027, as the first license date for API Service Category CL-4 and API FB-4

API LSG members will be able to review and vote on these elements during a 30-day period before final adoption. Prior to this review period, each of the above actions was reviewed and approved by the Diesel Engine Oil Advisory Panel (DEOAP) and the PC-12 New Category Development Team (NCDT) for the ASTM D4485 updates. The recommendations were then forwarded to the API LSG.

Going forward, as PC-12 development continues, API and fleets will need to prepare to transition to the new categories. To do so, the API licensee portal will open many months prior to Jan. 1, 2027, which is the first license date. This will allow licensees to enter new API CL-4 and API FB-4. API will issue a notification to licensees once early entry becomes available.