API Clarifies New Diesel Oil Categories

Technical Bulletin 1, issued by Kevin Ferrick, API’s senior manager for engine oil licensing, addresses the adoption of new diesel engine oil service categories API Service CK-4 and API Service FA-4 into the API 1509 Standard.

API Service CK-4 and API Service FA-4 can be licensed for use in the upper portion of the American Petroleum Institute’s trademarked service symbol, or “donut,” starting Dec. 1, 2016. Marketers can begin to identify oils that meet the new categories prior to the first licensure date but cannot make any claims or even imply that the oils are certified for CK-4 or FA-4 in advance of that date.

The American Petroleum Institute approved the new diesel engine oil service categories CK-4 and FA-4 in early February.

Marketers that want to claim their products are licensed by API as meeting CK-4 or FA-4 must apply for licensing through the online application system.

API will process applications as they are received, but the right to claim API licensing against the CK-4 or FA-4 standard will not be allowed until Dec. 1, 2016, and no marketers may display API CK-4 or FA-4 in the API donut until that date.

In addition, oil marketers may license oils meeting API Service CK-4 as API Service CJ-4, API CI-4 with CI-4 PLUS, CI-4 and CH-4, because CK-4 is backwards compatible with these earlier categories. However, care must be taken not to include FA-4 in this labeling practice since it is not generally backwards compatible. This is the result of FA-4’s unique high-temperature, high-shear rate viscosity limits, which are lower than minimum values for other categories.

With regard to so-called “universal” oils having both heavy-duty diesel and light-duty gasoline engine credentials (such as API CJ-4/SM), API has balloted the question of whether or not the new categories will allow this. While the results of the ballots are not available, there seems to be general agreement that no waiver of the phosphorus limit will be granted when API category SL is shown after CK-4 or FA-4. For categories SM and SN, sulfur and TEOST MHT cannot be waived either, in addition to the prohibition on phosphorus limit waiver.

Marketers are free to identify qualifying oils as “meeting” API Service CK-4 or API Service FA-4 prior to the Dec. 1 first licensing date, but must avoid statements that imply API has certified or licensed the oils yet. Instead, a marketer may use this type of statement: “…developed to meet the soon-to-be-available CK-4 and FA-4 categories….”

This is the latest step in the process to introduce these two new categories, which have been under development since 2011. On May 16, API announced the introduction of a modified service symbol donut to help consumers identify API FA-4 diesel engine oil, which is specifically designed to protect the next generation of diesel engines beginning with the 2017 models. API approved the two new diesel oil standards in early February.

Category CK-4 describes oils for use in high-speed four-stroke cycle diesel engines designed to meet 2017 model year on-highway and Tier 4 non-road exhaust emission standards, as well as for previous model year diesel engines. These oils are formulated for use in all applications with diesel fuels ranging in sulfur content up to 500 parts per million (0.05 percent by weight). However, the use of these oils with greater than 15 ppm (0.0015 percent by weight) sulfur fuel may impact exhaust after treatment system durability and/or oil drain interval.

Category FA-4 describes certain SAE XW-30 oils specifically formulated for use in select high-speed four-stroke cycle diesel engines. These oils are blended to a high temperature high shear viscosity range of 2.9 cP-3.2 cP to assist in reducing greenhouse gas emissions and improving vehicle fuel economy. Category FA-4 oils are not interchangeable or backwards compatible with any earlier categories.

Users should refer to engine manufacturer recommendations to determine if API FA-4 oils are suitable for use. API FA-4 oils are not recommended for use with fuels having greater than 15 ppm sulfur. For fuels with sulfur contents greater the 15 ppm, users should refer to engine manufacturer recommendations.