PC-11. Driving DURONTM

PC-11 becomes API CK-4 and FA-4

PC-11 (Proposed Category 11) has been the biggest change in heavy duty diesel engine oils in a decade. The demands of PC-11 and new category tests have been the driving force behind the development of DURON Next Generation.

Now, PC-11 has become the two new categories that will define heavy duty engine oils for years to come:


Improved performance and backwards-compatible for older engines


Primarily for use in the next generation of advanced diesel engines

Why are the changes happening?

API CK-4 and FA-4 are driven by legislative changes and the world’s engine manufacturers, who must:

Tough new tests

For engines to meet the emissions, efficiency and fuel economy goals of the future, they’ll need the help of the next generation of oils.

To meet the standards of API CK-4 and FA-4, those oils must pass some tough new tests. Watch John Pettingill Petro-Canada Lubricants Research & Development Product Specialist explain what they are and how they can impact your engine.

Oxidation control

Oxidation leads to decreasing engine protection, lower fuel efficiency and fewer miles between oil drains.

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Aeration control

Aeration directly affects oil performance, potentially causing engine wear, poor oil performance, and ultimately, greater operating costs.

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Shear stability

Shearing of the engine oil can mean oil becomes thinner and less protective to the engine.

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Frequently Asked Questions

PC-11, or Proposed Category 11, introduces two new quality levels for heavy duty diesel engine lubricants:

  • PC-11A will replace the current API CJ-4 engine oils and deliver increased engine protection benefits and is known as API CK-4
  • PC-11B is a new category of lower viscosity heavy duty diesel engine oils designed to deliver the same increased engine protection benefits as API CK-4 and even further enhanced fuel economy. This new category is known as API FA-4. API FA-4 is designed to allow engine manufacturers to improve the fuel economy of their engines which will reduce their amount of greenhouse gas emissions (GHG)

These improvements support the new National Highway Traffic Safety Administration (NHTSA) regulations that will go into full effect in 2018.

PC-11 oils will be introduced in 2016. The official first allowable use for the API CK-4 and API FA-4 designations is December 1, 2016.

Most North American OEMs will revise their own specifications to complement the API category.

A significant increase in oxidation protection will be the primary benefit. Many OEMs are employing new engine design strategies that result in engines operating at higher temperatures. As a result, there is a greater strain on an engine oil to provide oxidation protection.

Improved aeration control and the ability to resist viscosity breakdown (by means of improved shear stability) are the other benefits of PC-11 engine oils.

API FA-4 will be a new category of lower viscosity heavy duty diesel engine oils for improved fuel economy and reduced GHG emissions primarily for on-road applications.

Shear stability was of concern since some multi-grade products, particularly SAE 15W-40 grades, in some applications, tended to allow a drop in viscosity after certain times of service in the field. A drop in the viscosity is not necessarily always due to shearing, nor does it necessarily mean the engine is at risk. DURON Next Generation is formulated to better withstand shear loss and in many cases it will help to maintain the proper viscosity grade that was carefully chosen.

Improved aeration control was requested particularly for off-road engines where, in some cases, more air than usual could become entrained in the engine oil. A high level of air entrainment is dangerous, particularly at the bearings where a suitable oil film is critical to protect the bearings.

Improvement in oxidation resistance has become necessary since newer engines are designed to run at higher temperature in order to improve operating efficiency. Higher temperatures accelerate the rate of oxidation and oil thickening, hence improved oxidation resistance is a necessary feature of PC-11 (API CK-4 and FA-4) oils.

Each oil must pass a rigorous qualification program complete with both engine and bench tests in order to meet the new category requirements. We have and will continue to invest millions of dollars and manpower hours to not only meet these requirements, but in many cases surpass them. We further supplement this with real world field testing in the most gruelling conditions to give operators absolute confidence in the performance of products.

Natural gas engines are not covered under PC-11, and have their own specifications set by the OEMs. The conditions in the combustion zone, the need for detergency and sulphated ash requirement are so different between diesel and natural gas engine oils that it is best to use the oil formulated to meet the OEM recommendation. We will continue to offer our DURON GEO LD 15W-40 for natural gas applications.

There are no new SAE viscosity grades, however API FA-4 oils will be introduced as a new lower viscosity SAE 10W-30 and 5W-30. This is in addition to the higher viscosity API CK-4 SAE 10W-30 oils.

API CK-4 SAE 10W-30 and 5W-30 oils offer a balanced approach to provide fuel economy improvements versus SAE 15W-40 while offering comparable engine protection in older and newer engines.

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