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.

The final limits for the new specifications were finalized at the end of 2025, and the new category of lubricants, called API CL-4 and FB-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. Emission system protection will also be a key component to the new specification.

The test development phase of the category began in December 2021 and the first licensing of the oils under the standard is January 1^st, 2027. Petro-Canada Lubricants’ DURON products will be ready to launch API CL-4 and FB-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 all 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 will 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 were two sub-categories of heavy-duty engine oil launched with 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, SAE 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 oils. These oils may be incompatible with hardware architecture operating on traditional HTHS levels; therefore, two separate sub-categories must be maintained. 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.

Although CL-4 oils will be backward compatible to former active C categories (ex: CK-4, CJ-4, etc.), FB-4 oils will not be backward compatible to FA-4 oils.

PC-12 oils will support fleets to continue their journey toward improved fuel economy and reduced carbon emissions. Expected to include 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.

PC-12 oils will also be formulated with lower SAPS (Sulfated Ash, Phosphorous and Sulfur) content relative to most current commercial PC-11 oils, hence they will be more emissions system friendly.

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.

PC-12 will build on the previous engine categories and continue advancing oil technology with a few further key upgrades: enhanced wear protection, improved oxidation control and optimized after-treatment protection. We are taking advantage of the opportunity to enhance several features of the DURON line to not only conform to new emission regulations, but also to take a step forward in product performance.

Enhanced Wear Protection – DURON will deliver robust protection to extend engine and asset life across the entire service interval.

Improved Oxidation Control – DURON will provide improved stability for longer oil life, supporting extended drain intervals and peak engine performance.

Optimized After-Treatment Protection – DURON will be formulated with advanced chemistry to help safeguard critical components like DPFs and SCRs, ensuring longer system life.

DURON Next Generation will include all of these enhancements and more.

As the launch of PC-12 oils is around the corner, there is much work to be done in preparation for its arrival. We will continue working with our industry partners and colleagues in readiness for its arrival, with our Technology team developing and testing our new formulations.

As part of the additional testing, Petro-Canada Lubricants completed an operational field trial on a prototype SAE 0W-20 in advance of PC-12 to push the boundaries of lubricant technology and offer even greater fuel economy and wear protection. Although a 0W-20 fluid won’t be required in the early stages of the PC-12 category, our Technology team has proven capabilities of our formulations, in anticipation of OEMs migrating to this lower viscosity grade.

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.