The Phillips 66 Guardol FE Diesel Engine Oil with Liquid Titanium protection additive is a premium quality, part-synthetic API FA-4 engine oil developed for fuel economy benefits in 2014 and newer engines. Guardol FE is formulated with a blend of synthetic and high-quality Group II base stocks and a proprietary low-SAPS additive package to provide outstanding engine protection in late model diesel engines. It is fortified with Liquid Titanium protection additive for enhanced oxidation resistance and protection against wear. This additive enhancement provides increased engine protection from a strongly bonded titanium shield formed on the surface of critical engine parts, despite lower HTHS requirements of FA-4.