The new specification is being developed to support OEMs requirement to meet upcoming NOx and greenhouse gas emissions regulations issued by the US Environmental Protection Agency (EPA).

In response to these upcoming changes, the Truck and Engine Manufacturers Association requested a new heavy-duty engine oil performance category, PC-12.

Although the final limits for the new specifications will be finalized by end of 2025, the new category of lubricants, expected to be called CL-4 will be formulated to help meet the performance needs of the latest engine and emissions systems technologies. This means that wear protection will be even more important, as will oxidation control, due to engines working harder with increased operating temperatures to help meet new regulation guidelines.

The test development phase of the category began in December 2021 and the first licensing of the oils under the standard is targeted for January 1^st, 2027. Petro-Canada Lubricants’ DURON products will be ready to launch API CL-4 products, meeting PC-12 requirements, on January 1^st, 2027.

PC-12 oils are expected to improve performance, maintain durability and continue the drive toward lower viscosity lubricants, which in turn will lead to improved fuel economy for fleet owners. This is due to lower viscosity oils reducing drag within the engine as well as pumping and rotational losses to improve efficiency and ultimately, fuel economy.

However, it’s important to note that PC-12 lubricants will face rigorous tests to ensure that the engine oils provide the vital lubrication and protection needed for internal components.

Similar to PC-11, the new category is expected to have two subcategories, including one which takes advantage of lower high temperature high shear (HTHS) oil viscosity (similar to API FA-4). This category will be designed for specific OEM hardware architecture and offer even lighter grades of lubricants (even SAE xW-20s) that will ultimately improve fuel economy even further.

One of the key changes to the new oils will stem from their chemical composition. In both PC-12A (CL-4) and PC-12B (FB-4) categories, there will be tighter limits on SAPS: sulphated ash, phosphorus and sulphur. The lower limits imposed are required to protect the aftertreatment systems of MY 2027 vehicles in order to achieve the targeted emission standards. That being said, due to additional durability requirements in the testing program, Petro-Canada Lubricants is confident that the reduced SAPS will not have a negative impact on the performance of the oil and its longevity in service. In Europe, lower SAPS have been the norm for years, with proven performance on and off road.

There are currently two sub-categories of heavy-duty engine oil available in the PC-11 category and these will be carried across to PC-12. Named CL-4 (PC-12A) and FB-4 (PC-12B), each category will based on high temperature high shear (HTHS) values.

The PC-12B oils developed will be formulated using lower viscosities, XW-30 and XW-20, and will enable superior fuel economy benefits.

Some Original Equipment Manufacturers (OEMs) have developed specific hardware architecture that can take advantage of lower HTHS oil viscometrics. These oils may be incompatible with hardware architecture operating on traditional HTHS levels; therefore, two separate sub-categories must be created. It’s again important to note that both categories face the same robust testing criteria and offer high levels of lubrication and protection for hardware.

PC-12 oils will support fleets continue their journey toward improved fuel economy and reduced carbon emissions. Expected to included even lower viscosity lubricants, fleets can anticipate reduced fuel costs and improved protection through the use of the latest lubricant technologies.

On top of boosting general performance, PC-12 oils will help OEMs meet the demands of upcoming (2027) greenhouse gas and fuel mileage regulations issued by the Environmental Protection Agency and the California Air Resources Board.

The new engine oils will undergo rigorous testing, similar to their predecessors, so that fleet owners can be reassured that all viscosity grades have very high levels of protection of the engine’s componentry.

As part of PC-12, new tests were developed to address the end of life of certain legacy tests. One of the new tests, the Cummins ISB, will be replacing the Mack T-11 engine test, which was designed to measure an oil’s viscosity increase due to soot over time. Another new test is the Detroit Diesel DD13 Scuffing Test, designed to measure piston and liner scuffing wear.

The addition of these new tests ensures renewed longevity for each engine test and addresses the realities of newer engine designs. As adjustments are made to the newly designed lubricants, it is critical that extensive testing is conducted in both a lab setting and in field trials to validate performance. Petro-Canada Lubricants is using that combination of bench testing, engine testing and field trials in diverse segments (ex: fleet, waste, construction, and mining) to support the launch of the new PC-12 engine oils.

As the launch of PC-12 oils is under two years away there is still much work to be done in preparation for its arrival, however, we will be working with our industry partners and colleagues in readiness for its arrival.

For example, Petro-Canada Lubricants has already completed an operational field trial on a prototype SAE 0W-20 in advance of PC-12 and in the event the viscosity is included within the upcoming specification. As we move closer to the introduction of PC-12, we look forward to undertaking additional trials where we can push the boundaries of lubricant technology to offer even greater fuel economy and wear protection.

In addition, we will be issuing more information in Q2-Q3 2026 to prepare our customers for this upcoming product introduction. Stay tuned!

Fleet owners should investigate equipment requirements and the impact these have on OEM engine oil recommendations in advance. This will allow fleets to begin exploring lower viscosity lubricants, such as SAE 10W-30 engine oils, which can improve engine efficiency, or low viscosity transmission and driveline fluids, which can also support fuel economy efforts.

Additionally, fleet owners should consider the type of equipment they may need to purchase. By doing this work now, the benefits offered by the category can be maximized once it arrives.

When making changes to your lubricants and greases it is crucial to seek advice from your original equipment manufacturer (OEM) and your lubricant technical service advisor. Our experts can provide industry insight on the development of the specification as well as tailored advice on what you should be doing to prepare your fleet.