The American Petroleum Institute's new diesel engine oil-service categories, API CK-4 and FA-4, will begin appearing in the marketplace on December 1.

New API Donuts denoting the categories will appear on licensed products and marketing materials allowing consumers to identify oils meeting CK-4 or FA-4, which are expected to be recommended in new owner’s manuals and by engine manufacturers.

The new specifications were designed to address the varying needs of engine technologies in aging, new, and in-use on- and off-highway applications to help diesel engine manufacturers meet stringent emissions and fule-mileage 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. “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 nine 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 backwards-compatible for most applications for which 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 backwards compatibility with on- and off-highway diesel engines for which engine manufacturers have recommended CJ-4. While not specifically backwards-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 anf fuel-mileage 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 the API website 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.