On Thursday, December 1, 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.
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.
As of this past Saturday, December 10, there were 69 API CK-4 licensed oils and 35 API FA-4 licensed oils on the API lists.
to view the licensed API CK-4 oils on the API list
to view the licensed API FA-4 oils on the API list
Oils will continue to be added to these lists as the licenses are granted. Therefore the number of licensed oils will continue to change.