The American Petroleum Institute announced last week the introduction of a trademarked special service symbol to help consumers identify the recently approved API FA-4 diesel engine oil, which is designed to protect the next generation of diesel engines. API approved FA-4 along with API CK-4 in February. This marks the second time the organization issued twin standards. The first was CF and CF-2 in 1994.
The FA-4 donut was developed to help truck owners who need FA-4 oils easily recognize the oil and distinguish it from CK-4 oils, said Kevin Ferrick, APIs senior manager for engine oil licensing
FA-4 and CK-4 emerged from the PC-11 heavy-duty diesel engine development process. Both were developed for model year 2017 and later engines, but CK-4 can be used in engines that run on fuel with up to 500 parts per million sulfur, though fuels above 15 ppm sulfur could cause deterioration of exhaust after treatment systems if drain intervals are not shortened. CK-4 is also backward compatible, meaning it may be substituted for earlier heavy-duty diesel engine oils.
FA-4 is not backward compatible and not recommended for use with fuels containing more than 15 ppm sulfur.
For CK-4, API retained the same donut trademark used with CJ-4 and earlier specifications. The symbol for FA-4 is based on the same design but divides the top half of the concentric circles into quarters, one of which is colored or shaded. APIs hope is that the FA-4 symbol is similar enough that truck operators and fleet managers will recognize it as an engine oil standard but different enough to distinguish it from CK-4.
Image: American Petroleum Institute
Many in the lubricant industry agree that end user confusion over engine oil standards is an ongoing issue, and individuals on the PC-11 New Category Development Team raised the concerns that the problem would be exacerbated once it became clear that PC-11 would be divided into two sequences.
The NCDT considered numerous proposals of how to identify the new category within the API system, including entirely new names for the category, a trademark symbol similar to the starburst API Certification Mark used for passenger car and light truck purposes, and other designations. The group even discussed a new SAE J300 viscosity category to define the fuel-saving category.
The final choice was made at the May API Lubricants Group meeting. Announcing the new symbol May 16, API displayed a sample with one quarter of the donut shaded red, but it noted that other colors and shades including black are also acceptable. Dimension requirements remain in effect, including that the outer circle diameter must be 1.9 times the inner circle diameter. The lower half of the service symbol space remains available for designations such as Resource Conserving.
API FA-4, while it meets all engine test requirements of API CK-4, has a lower threshold for high temperature high shear viscosity than the API CK-4 minimum of 3.5 centiPoise. This value is below the minimum for all earlier categories where HTHS viscosity is specified. This means that API FA-4 will initially need to be specified by Engine Manufacturers Association member companies to be used without potential breeches of engine warranty requirements.
Licensing of the new oils is scheduled to begin on Dec. 1.