Delo 400 XLE SAE 15W-40 with ISOSYN Advanced Technology is synthetic blend API CK-4 heavy duty engine oil specifically formulated for better oxidation, wear protection and piston deposit control for on highway and off highway applications, including 2017 greenhouse gas (GHG 17) compliant diesel engines with lower CO2 emissions, in addition to 2010 compliant low emission 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. Delo 400 XLE SAE 15W-40 with ISOSYN Advanced Technology is also recommended for off highway Tier IV emission compliant engine applications where an SAE 15W-40 viscosity grade is required. It is formulated for newer engines with Selective Catalytic Reduction (SCR), Diesel Particulate Filter (DPF) and Exhaust Gas Recirculation (EGR) systems. Additionally, Delo 400 XLE SAE 15W-40 is recommended for use with transmissions that require the Allison TES-439 specification in heavy duty off-road applications. It is fully compatible with previous engine models and previous API Oil Service Categories.