Ford Motor Co.’s Ron Romano said that the development of the Ford 6.7L valve train wear test will be completed in the first quarter of 2017. The Ford 6.7L valve train wear test is one of the tests required in Ford’s WSS-M2C171-F1 specification for service-fill diesel engine oil.

The WSS-M2C171-F1 specification at this time will be recommended for servicing all Ford North American diesel vehicles, F-Series Super Duty and Transit, said Romano, who is the service lubricants technical expert for the Ford Customer Service Division, Service Product Development, based in Allen Park, Mich., U.S.A.

Last October, Ford issued a position statement on CK-4/FA-4, the new heavy-duty engine oil specification which will be licensed by the American Petroleum Institute (API) beginning December 1, 2016.

“Ford will not be recommending the use of CK-4 motor oils in any Ford diesel engines, new or old,” the statement said. “Testing Ford has done on some CK-4 formulations have shown inadequate wear protection compared to CJ-4 formulations developed and licensed before 2016,” the statement continued.

However, F&L Asia has learned that other CK-4 additive formulations are available that did not result in wear problems in the 1,000-hour test done on the Ford 6.7L engine.

Nonetheless, Ford said that it “will now be recommending oils that meet an OEM specification, Ford Material Engineering Specification WSS-M2C171-F1. The customer should use an oil showing that it meets this specification.”

In the meantime that the development of the Ford 6.7L valve train wear test is not yet complete, Ford said that “an oil showing CJ-4 in the API donut without showing CK-4 would be acceptable for service even if not showing WSS-M2C171-F1. Field experience and Ford testing has shown that these older CJ-4 formulations provide acceptable 6.7L engine protection.”

According to API’s Kevin Ferrick, “CJ-4 is not going to be made obsolete when CK-4 is introduced. It should be available for the foreseeable future, so API-licensed CJ-4 oils will also be available to satisfy Ford’s recommendation for its diesel engines.”

API CK-4 oils are meant to be backward compatible with API CJ-4 oils. Both CK-4 and CJ-4 have the same limits on phosphorus, which is a maximum limit of 0.12% by weight and no minimum limit. The problem seems to arise when an API CK-4 oil also has an API SN claim on the label, and again for some, not all, additive technologies.

Motor oils designed for cars, vans and light trucks with gasoline engines fall under API’s “S” (Service) categories. Motor oils designed for heavy-duty trucks and vehicles with diesel engines fall under API’s “C” (Commercial) categories.

Because fleet owners usually prefer to have the convenience of using one oil for both their diesel and their gasoline vehicles, and phosphorus can be detrimental on three-way catalysts which are used in gasoline vehicles, typical motor oil formulations with “dual claim,” such as API CK-4/SN, would have a phosphorus content of 0.08% by weight to protect the gasoline engine’s aftertreatment device from being poisoned by the phosphorus.

To view the Ford Material Engineering Specification WSS-M2C171-F1, click on this link.