PC-12 on track for 2027

As heavy-duty diesel technology evolves to meet the requirements of tightening emissions regulations and demands for improved fuel economy, engine oils must keep pace with the changes. Next generation engine oils need to not only deliver improved oxidation control and enhanced wear protection but also must protect engine and aftertreatment hardware for longer periods, while contributing to fuel economy improvements. That’s a lot of requirements and delivering all of them is harder to do as stricter chemical composition limits are introduced in the new category.

You can read more about the drivers for PC-12 here, but in summary, a real step change in requirements is expected from the US Environmental Protection Agency including:

• 75% less NOx

• 50% less particulate matter

• 83% increase in the useful life for aftertreatment systems

The timing of PC-12 is being driven by the need for heavy-duty OEMs to comply with the new emissions standards, which are expected to go into effect for model year (MY) 2027 diesel engines.

The industry is currently navigating the technical demonstration phase, where additive companies (Adcos) show that their formulations can meet the PC-12 specification requirements. This is scheduled to finish by the end of 2025, which means 2026 will be the American Petroleum Institute (API) mandatory waiting period, a crucial period for customers, especially fleet operators, to prepare for the transition to the new PC-12 standards.

What’s new in PC-12

The new PC-12 category is designed to protect both on-highway and off-highway heavy-duty diesel engines. This means it must perform across a wide range of duty-cycles and environmental conditions and meet different wear protection requirements.

PC-12 is split into two categories, PC-12A and PC-12B, that align with the viscosity divide that exists today with API CK-4 and FA-4.

The Truck and Engine Manufacturers Association (EMA) will allow the use of PC-12A products in applications where API CK-4 oils had previously been specified and similarly for PC-12B to API FA-4. For oil marketers, products meeting PC-12A will also be able to claim API CK-4, but the ability for products meeting PC-12B to also claim API FA-4 is under review.

The category contains one new test development. The Cummins ISB viscosity test that has been included to replace the Mack T-11 for soot related viscosity increase. Infineum has been heavily involved in the test's development - read more here.

A major area of focus for next generation lubricants is delivering improved protection and performance for aftertreatment devices. This is particularly important as their useful life has been extended from 435,000 to 800,000 miles.

To ensure formulations help to prolong the functionality of the aftertreatment device, tighter chemical limits are being introduced.

There are a number of other key changes for PC-12, which include:

A number of changes to the tests and limits for PC-12 are being made and a summary of what can currently be expected is shown in the table below. While the target values (shown in red) have been included for information, the actual pass/fail limits will not be set until after the technical demonstration period.

Enlarge view

Key benefits of PC-12

In addition, to ensuring hardware durability over longer periods, the introduction of a new category provides a good opportunity to enhance lubricant performance in other areas such as longer oil drain intervals, improved fuel economy and better engine deposit protection. In our view PC-12 will deliver benefits in several key areas.

Infineum in action

Our focus has been on understanding the new specification requirements and how to meet the specific challenges for PC-12 around wear, cleanliness, soot handling and oxidation control with tighter chemical limits.

Through 2025, whilst industry engine and bench testing nears completion, our PC-12 technology is being evaluated in the field in both on- and off-road applications across a broad range of viscosity grades and base oils to meet the requirements of our customers.

We will be ready to launch PC-12 products by the end of the year in line with the January 1 2027 first allowable use (FAU) date.

Life after PC-12 FAU

Infineum Insight will keep you informed of PC-12 progress as industry works to complete all the remaining tasks. In our upcoming articles we will also look at life after PC-12 FAU, including the definition of success, the future of API CK-4 and older categories, the potential lifespan of PC-12 and if a PC-13 or modified PC-12 can be expected in the future.

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

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