Delo 400 XLE SB SAE 15W-40 with ISOSYN Advanced Technology is a premium synblend,  heavy-duty engine oil optimized with a mixture of synthetic and conventional base stocks designed for extended drains (up to 1.5x OEM standard drain interval) and mixed fleets. It is recommended for naturally aspirated and turbocharged, four-stroke diesel engines and four-stroke gasoline engines in which the API CK-4 or API SN service category and SAE  15W-40 viscosity grades are recommended. It is also approved by many of the major heavy-duty Original  Equipment Manufacturers (OEM), meeting their latest engine oil specifications. Delo 400 XLE SB SAE 15W-40 with ISOSYN Advanced  Technology is an API CK-4 heavy-duty engine oil specifically formulated for on highway applications,  including 2017 greenhouse gas (GHG 17) compliant diesel engines with lower CO2 emissions, in addition to  2010 compliant low emission and off-highway Tier IV  diesel engines with Selective Catalytic Reduction  (SCR), Diesel Particulate Filter (DPF) and Exhaust Gas  Recirculation (EGR) systems calling for SAE 15W-40  premium heavy duty motor oil. Additionally, Delo 400 XLE SB SAE 15W-40 has excellent performance in Allison heavy-duty transmission units requiring Allison TES-439 approval and provides excellent shear stability and component protection. It is fully compatible with previous engine models and previous API Oil Service Categories.