Since being launched on December 1, 2016, API CK-4 and FA-4 diesel engine oils have become readily available for the trucking, construction and agriculture industries. The American Petroleum Institute says it has licensed approximately 654 CK-4 and 83 FA-4 oils which ensure that the newest categories of diesel oil for use in on- and off-highway vehicles and equipment are available in the marketplace.

OEM/Lube News did a quick check right before press time and those numbers are now actually up to 667 CK-4 Licensed Oils and FA-4 Licensed Oils remaining at 83.

OEM/Lube News published a story on July 3, 2017 entitled "API CK-4 Licenses Issued Now Stands at 523" in which at that time, we stated the number of CK-4 licenses issued to date stand at 523 and the number of FA-4 licenses issued to date stand at 76.

The number of approved oils for both categories from large, medium, and small oil marketers has grown consistently throughout the year. API says it expects that the licenses for both oils will continue to increase and that FA-4 will see growth as more new engines that require lower viscosity engine oils are placed in service in the coming years.

API CK-4 oils succeeded CJ-4 engine oils and are backward compatible diesel oils. CK-4 provides improved shear stability, oxidation resistance, and aeration control over CJ-4 in the familiar SAE 15W-40 and 10W-30 viscosity grades. Lower viscosity FA-4 oils, which meet the same performance standards as CK-4 oils, have been developed to provide engine manufacturers with a tool that will help them meet more stringent fuel economy and greenhouse gas emissions requirements.

According to the API, CK-4 and FA-4 oils are available in bulk through diesel oil distributors for trucking, construction and agriculture operations and in packages through retailers. API recommends that shops, fleets and others purchasing diesel engine oils confirm that the oil is licensed for the CK-4 or FA-4 category, which means the maker is warrantying that it meets API standards. Those seeking to verify that an oil is licensed can contact the API directly or look on the API website, the API stated.