The American Petroleum Institute (API) monitors the quality and applicability of engine oils through the occasional introduction of performance categories - or, a set of performance standards - that meet the demands of new engines. API FA-4 performance category was established in 2017.
API FA-4 diesel engine oils are designed for next generation engines to provide maximum fuel economy without sacrificing engine protection.
Unlike previous API engine oil specifications, API FA-4 maynot be backwards compatible as a replacement for previous API oil requirements such as CK-4 and CJ-4. For older model engines check with the OEM before using API FA-4 service category engine oils.