PC-12 moving forward

There has been a lot of industry activity on the development of the new PC-12 heavy-duty engine oil specification. Back in early December, industry stakeholders met under the auspices of ASTM International (ASTM) and the American Petroleum Institute (API) to review comments and progress the proposed final requirements for PC-12. Finalisation of heavy-duty engine oil specifications requires both ASTM and API ballots. API 1509 Annex D describes the responsibilities of stakeholder groups in developing new diesel oil performance standards for API C and F Service Categories.

Previously, the ASTM Heavy Duty Engine Oil Classification Panel (HDEOCP) issued a ballot for adoption of the proposed PC-12 specification into ASTM D4485, which outlines the performance requirements of engine oils for light-duty and heavy-duty internal combustion engines. During the December meeting, the ASTM HDEOCP reviewed stakeholder responses and approved the ballot. With minor editorial change, the ASTM HDEOCP recommended the PC-12 specification progress to a final ballot at ASTM D02.B0.

The balloted PC-12 specification, including tests and limits, for API CL-4 and FB-4 can be found in Table 7 and Table 8 respectively.

Click here to download your pdf copy of these tables.

Shortly thereafter, the API Diesel Engine Oil Advisory Panel (DEOAP) convened. This was to review the status of all PC-12 deliverables as managed by the New Category Development Team (NCDT) and agree on recommending, to the API Lubricant Standards Group (LSG), the adoption of PC-12 into API 1509 as new Heavy Duty Engine Oils Categories API CL-4 and API FB-4. With User Language updates at the request of Engine Manufacturers Association (EMA) stakeholders, the recommendation was approved.

Three ballots issued

Based on the API DEOAP recommendation, API LSG members approved three ballots to issue:

Ballot 1 - Allow the use of API CL-4 and API FB-4 standard in the API Service Symbol 'Donut'.

Ballot 2 - Approve the API CL-4 and API FB-4 Standards User Language for inclusion in API 1509.

Ballot 3 – Adopt January 1 2027 as the first date that API CL-4 and API FB-4 Engine Oils may be licensed.

On February 12 2026, API LSG reviewed and accepted the results of these ballots. All ballots were deemed passing and effective as of the ballot issue date of December 11 2025. These updates will be included in the next published version of API 1509.

In support of the targeted first licensing date, the American Chemistry Council (ACC) announced the conclusion of the PC-12 Technology Demonstration Period effective December 10 2025.

These actions allow the PC-12 development process to enter the API Mandatory Waiting Period and enable oil marketers to display API CL-4 and API FB-4 in the API Service Symbol 'Donut' from January 1 2027.

In summary, the industry has essentially completed all stages of the development process for the PC-12 specification. See the animated PC-12 development timeline below.

We are now in the required API Mandatory Waiting Period, leading up to the January 1 2027 first licensing date for the new API CL-4 and FB-4 categories. These two new categories have been carefully designed to ensure continued engine and aftertreatment protection for heavy-duty engines.

Click here to find out more about the key changes in our PC-12 resource hub.

Infineum is ready to support you

Infineum PC-12 technology has been evaluated in extensive on-road and off-road vehicle field trials, across a broad range of viscosity grades and base oils. This activity means we will be ready to launch PC-12 products in line with the January 1 2027 first allowable use date to meet the requirements of our customers. Please contact your Infineum representative to find out more.

Make sure you stay up to date –sign up here to receive regular updates to your inbox and visit our PC-12 resource hubfor more information.

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