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) and the California Air Resources Board (CARB).

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

While the details of the new specification are yet to be finalized, PC-12 lubricants 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, 2027.

On April 12, 2023, the highly-anticipated Phase 3 of the federal Greenhouse Gas (GHG) Standards for heavy-duty vehicles was announced by the EPA and taken under review by the American Trucking Association. Although the details of what these changes will mean are not yet entirely clear, what we do know is that stringent emission standards will be put in place for all vehicles, surpassing the benchmarks established during 2016's GHG Phase 2. (Click here for more information).

Additionally, on July 6, 2023, CARB and a number of heavy-duty engine and vehicle manufacturers announced a joint agreement: the Clean Truck Partnership. Under this agreement, CARB has committed to allowing OEMs greater flexibility under their Heavy-Duty Engine and Vehicle Omnibus Regulation in addition to more closely aligning with EPA’s own heavy-duty regulations (Click here for more information). Both these changes in criteria are likely to have an impact on the development of PC-12 and the corresponding testing procedures it will need to undergo.

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 (possibly even SAE 0W-20s) that ultimately improve fuel economy.

There are currently two sub-categories of heavy-duty engine oil available in the PC-11 category and this is expected to be carried across to PC-12. Each category is based on high temperature high shear (HTHS) values.

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. This will likely see these lubricant categories face new tests developed in line with the latest engine architecture.

Although still to be determined, proposed tests include development for an engine scuffing test and a new wear test, however, these still have some hurdles to clear before being accepted for PC-12.

Chemical limits are also still being investigated. There are several options currently being explored including keeping within existing limits, aligning the limits with ACEA, or pushing the boundaries of the lubricant, for example, aiming for a lower ash content.

As the launch of PC-12 oils is under four 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 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.

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 over the next few years. 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.