AMSOIL Premium API CJ-4 Synthetic 5W-40 Diesel Oil (Part # DEO)Maximum Fuel Economy and Extended Drain Intervals in Ultra-Low Emission Diesel Engines.AMSOIL Synthetic 5W-40 Diesel Oil (DEO) is the premium choice for API CJ-4 emission-qualitydiesel oil required by model-year 2007 and newer diesel engines.Exceeds Emission System RequirementsAMSOIL Synthetic 5W-40 Diesel Oil is a low-sulfated ash formulation that exceeds the requirements for low-emission diesel oil. It is compatible with all exhaust treatment devices, is designed to extend the service life of diesel particulate filters (DPF).Extended Drain PerformanceAMSOIL Premium 5W-40 Diesel Oil can extend drain intervals far beyond those recommended for conventional petroleum oils.Its unique synthetic formulation and long-drain additive system (10.4 TBN) deliver superior engine protection, cleanliness and performance over extended drain intervals. AMSOIL Synthetic 5W-40 Diesel Oil provides maximum protection for up to 3X the OEM-recommended drain interval, even further with oil analysis.Look up your application or order on my Amsoil Dealer Website