Kendall® Super-D XA (eXhaust Advantage) Diesel Engine Oil with Liquid Titanium protection additive is a premium-quality, part-synthetic API CK-4 engine oil developed for use in four-stroke diesel engines designed to meet 2007 and later EPA on-highway exhaust emissions standards. It is specially formulated for compatibility with exhaust aftertreatment systems using diesel particulate filters (DPF), diesel oxidation catalysts (DOC), and/or selective catalytic reduction (SCR). It is back-serviceable for use in pre-2007 diesel engines.