Phillips 66® Guardol Fleet EC (Emission Compatible) Diesel Engine Oil is an API CK-4 engine oil developed for use in four-stroke cycle diesel engines designed to meet 2007 and later EPA on-highway exhaust emissions standards.

It is specifically formulated for compatibility with exhaust aftertreatment systems that use diesel particulate filters (DPFs), diesel oxidation catalysts (DOCs), and/or selective catalytic reduction (SCR). It is backward serviceable for use in pre-2007 diesel engines.

Available in multiple sizes, including jugs, pails, and drums. Ideal for farms, fleets, and repair shops.