The trucking industry's transition toward next-generation engine performance is officially underway. The American Petroleum Institute (API) on Wednesday said it has moved ahead with development of its PC-12 specification, setting a timeline for the oils for next generation diesel engines.
The road to PC-12: key developments
Following a series of high-level technical reviews, the API Lubricants Standards Group (LSG) has greenlit three critical actions that effectively solidify the framework for the new categories:
- Standardization approved: The technical requirements for PC-12 have been accepted, aligning with ASTM D4485 standards.
- New designations defined: The industry is officially introducing two new categories: API CL-4 and API FB-4.
- Launch date: Mark your calendars for January 1, 2027. This is the official First License Date when these oils will be commercially available with the API donut.
What fleet managers need to know
While current CK-4 and FA-4 formulations focused on the transition to 2017 emissions standards, PC-12 will be engineered for the much stricter EPA 2027 regulations, which mandate a 75% reduction in NOx and a 50% reduction in particulate matter.
API CL-4 will be the safe choice for mixed fleets. It is designed to be fully backward compatible with engines currently using CK-4, CJ-4, and older oils.
API FB-4 is the high-efficiency oil. Like FA-4 today, it will have limited backward compatibility and be formulated for model year 2027 and newer engines (or those specifically approved by the OEM). While 10W-30 is currently the fuel-economy standard for many fleets, the FB-4 category will introduce SAE 0W-20 and 5W-20 to the heavy-duty market as ultra-low viscosity oils reduce internal engine friction to meet aggressive greenhouse gas reduction targets.
Industry readiness & timeline
To prevent a bottleneck at launch, API has announced that its licensee portal will open several months ahead of the 2027 deadline, allowing oil marketers to register CL-4 and FB-4 early, ensuring that when the calendar flips to 2027, the supply chain is already primed.
What’s next?
We are now entering a 30-day electronic ballot period where final feedback will be gathered from industry stakeholders. Once finalized, the transition from lab testing to real-world shelf availability begins.
