Change Is Coming – New Diesel Oil Standards

*See note on Ford Diesels at the end of this page


Beginning in 2007, Diesel engines required oils rated CJ-4 while Diesels manufactured prior to 2007 could continue to use CI-4 rated oils.  On or after December 1, 2016 (once existing stocks are depleted) you will begin seeing CK-4 rated Diesel oils on the shelves.  The new CK-4 oils are backward compatible and for use in all Diesel engines specifying CF-4, CG-4, CH-4, CI-4, and CJ-4 oils as well as 2017 and later Diesels specifying CK-4 oils.  However, starting in 2017, Diesel Engine Manufacturers may also begin specifying FA-4 Diesel Oils.  These oils ARE NOT BACKWARD COMPATIBLE with Diesel engines built prior to 2017.  WHY – Because the EPA has mandated lower emissions and better fuel economy.   To accomplish this manufacturers designed their engines to use  lighter viscosity oils, such as 0w-40, 5w-30 & 10w-30 as opposed to the traditional 15w40 diesel oils.  

So, what does this mean to you?  

  • If you have only 2017 (or newer) diesels, you can use either the CK-4 or FA-4 oils.  For better fuel economy use the FA-4 oils.
  • If you have both 2017 and older diesels you can simplify you inventory and prevent possible lubricant mistakes by using the CK-4 oils in everything.  If you choose to use the FA-4 oils in the newer vehicles, you will have to make sure it doesn’t get put into the older engines as it may not provide the needed engine protection at the lower viscosity.
  • If you have only 2016 or older diesels, use the CK-4 oils.

While it sounds confusing, the following chart may help.

*While Ford participated in the development of the CK-4 and FA-4 Standards, they decided to introduce their own lubrication standard for use in Ford diesels.  The following article appeared in the November 9, 2016 edition of “Lube Report.”



In a surprise move, Ford has issued a new diesel engine oil service fill specification, WSS-M2C171-F1, covering all Ford diesel engines. This specification specifically disallows the use of API CK-4 and FA-4 categories, which were adopted by the auto and lubricant industries earlier this year. Ford’s specification identifies API CJ-4 category oils issued before 2016 as acceptable for use in its vehicles until the Ford 6.7L diesel engine test is completed and approved by ASTM.

Ron Romano of Ford notified the industry at an Oct. 26 meeting of the Diesel Engine Oil Advisory Panel – a stakeholder group which represents engine builders and oil and additive companies – that 6.7L engines tested on CK-4 and FA-4 formulations had experienced valve train wear not encountered with CJ-4 formulations. The CJ-4 formulations in question contained more than 1,000 parts per million phosphorus, an effective antiwear ingredient, while the CK-4 and FA-4 formulations were below that threshold. As a result, Ford declared that it has wear concerns about the use of CK-4 and FA-4 formulations with less than 1,000 ppm phosphorus in new and older Ford engines.

In a statement released to the general public at the Oct. 26 DEOAP meeting, Ford said FA-4, which was developed for heavy-duty diesel truck operators looking to enhance fuel economy, is unsuited for any diesel-fueled Ford trucks because its viscosity is too low. The company added that neither will it recommend CK-4 oils because of the wear issue.

“Testing Ford has done on some CK-4 formulations has shown inadequate wear protection compared to CJ-4 formulations developed and licensed before 2016,” the company said. While stating that it will continue to recommend CJ-4 oils with more than 1,000 ppm phosphorus, Ford advised that such products are acceptable only if their packages do not display CK-4 in the American Petroleum Institute’s donut logo, which would indicate they also meet the latter category. The company added that such products may not be available on the market for long.

“This oil would most likely be an older CJ-4 formulation, developed and licensed prior to 2016,” the position statement said. “These oils could be around for about a year after CK-4 licensing begins, Dec. 1, 2016.”

Historically Ford has always recommended API diesel categories. The company called for API to change CK-4 and CJ-4 to include a minimum phosphorus limit of 1,000 ppm. It are also recommended that if no phosphorus requirement is added to CK-4 or CJ-4 then API should require oils with less than 1,000 ppm phosphorus be labeled as low phosphorus.

Chevron Lubricants’ Shawn Whitacre, chairman of ASTM’s Heavy Duty Engine Oil Classification Panel, which is responsible for the engine tests that support CK-4, recalled that Ford first voiced concerns in January 2015, based on two tests it conducted during 2014.

“They believed, and still do, that the wear mechanism in their 6.7L is not addressed by the three existing wear tests in the category,” Whitacre told Lube Report. “At the time, they expressed preference for tighter limits on phosphorus content in CK-4 since they were committed to ensuring that their products could accept industry spec oils. Further, they expressed commitment to develop an engine test based on their in-house experience, much akin to how Daimler Truck North America has continued to develop the DD13 Scuffing Test.”

At the DEOAP meeting in Baltimore Oct. 26, Whitacre said, Ford proposed adding a minimum phosphorus level to the new API categories, along with mandatory labeling of phosphorus levels. But “neither proposal seemed to garner broad industry support,” and afterward Ford released its position paper.

Ford’s spec, WSS-M2C171-F1, is not yet complete. It will be based on CK-4 but will also include a valve train wear test run on a 6.7L engine. That test is still under development, and the company expects to complete it during the first quarter of 2017 and then turn it over to ASTM. Ford will have an approval program for this specification and will publish a list of approved products.

Until the 6.7L engine test is completed, Ford will approve CJ-4 formulations licensed before January 2016 if they contain 1,000-1,200 ppm phosphorus and an antioxidant boost to meet the CK-4 limits on a Volvo T-13 test. Formulators may also ask Ford to approve alternative testing on a 6.7L engine on a case-by-case basis.

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