New API Certified CK-4 and FA-4 Diesel Engine Oils Are Available Beginning December 1

March 2017

WASHINGTON… Beginning December 1, 2016. the American Petroleum Institute’s (API) new diesel engine oil standards, API CK-4 and FA-4, began appearing in the marketplace on licensed products and marketing materials. This means consumers will be able to easily identify the API CK-4 or FA-4 category oils that are expected to be recommended in new owners’ manuals and by engine manufacturers.

Earlier in 2016 API’s Lubricants Group approved the new API CK-4 and FA-4 specifications to address the varying needs of engine technologies—aging, new, and in use, both on- and off-highway—and to help diesel engine manufacturers meet more stringent emissions requirements.

“December 1 is an industry milestone as it marks the first day new API CK-4 and FA-4 engine oils can be marketed and sold on retail shelves or in bulk,” said Kevin Ferrick, Senior Manager of API’s Engine Oil Licensing and Certification System (EOLCS). “The time between approval of the categories last winter and the first licensing on December 1 gave large, medium, and small oil marketers the ability to test their new formulations and ready them for market. This signals the culmination of almost 9 years of cross-industry collaboration in the development of the new standards.”

API CK-4 oils will replace current API CJ-4 engine oils and will be backward compatible with most applications where engine manufacturers currently recommend CJ-4. The new CK-4 oils will provide a number of improvements over CJ-4, including improved shear stability, oxidation resistance, and aeration control. API FA-4 oils will provide similar improvements over CJ-4 oils, but it is important to note that FA-4 oils are only intended for use in newer on-highway diesel engines. FA-4 oils will have limited or no backward compatibility with on- and off-highway diesel engines where engine manufacturers recommended CJ-4. While not specifically backward compatible, FA-4 oils are expected to play an important role in some current and new diesel engines by protecting those engines and at the same time helping them meet more stringent emissions requirements.

CK-4 and FA-4 oils are designed for different applications. This means technicians and consumers will need to check their owner’s manuals or with engine manufacturers to determine which oil is right for their vehicle. API developed two visually different API Service Symbol Donuts so that consumers can easily distinguish between the two categories. The new API FA-4 Donut features a shaded section to differentiate API FA-4 oils from CK-4 oils. The API CK-4 Donut will look the same as the current CJ-4 Donut.


To find out if you are supposed to use CK-4 or FA-4 oil, check with your owner’s manual and your engine manufacturer. You can also visit www.DieselOilMatters.com for more information about the new API CK-4 and FA-4 service categories and their use in on- and off-highway diesel vehicles and equipment.

API CK-4 and FA-4 Background

These new oil standards were developed to better protect new and older engines, improve engine oil performance, and help engine manufacturers meet 2017 government emissions standards. CK-4 and FA-4 improve upon existing standards by providing enhanced protection against oil oxidation and engine wear, particulate filter blocking, piston deposits, and degradation of low- and high-temperature properties. The new categories are the result of several years of collaboration between engine manufacturers, API’s Lubricants Group, the Truck & Engine Manufacturers Association (EMA), and the American Chemistry Council (ACC).

About American Petroleum Institute

API is the only national trade association representing all facets of the oil and natural gas industry, which supports 9.8 million U.S. jobs and 8 percent of the U.S. economy. API’s more than 650 members include large integrated companies, as well as exploration and production, refining, marketing, pipeline, and marine businesses, and service and supply firms. They provide most of the nation’s energy and are backed by a growing grassroots movement of more than 30 million Americans.