The Guardol FE product is warranted for use in 2010 and newer Detroit Diesel engines and 2014 and newer Cummins, PACCAR, Navistar, Volvo/Mack engines.

Source: https://www.pressnews.biz/@bellamanda/phillips-66-guardol-fe-diesel-engine-oil-has-extended-its-limited-product-warranty-kn8rwdd5n3xw