DAUER DSX DIESEL SYNTHETIC BLEND 15W40 is premium quality oil. It is recommended for trucks with turbo and non-turbocharged engines; for the new EGR and low emission engines as well as older models. Our formula exceeds the requirements of API CJ-4/SN service classification and meets API CI-4 Plus, CI-4, CH-4, CG-4, CF-4, CF-2, CF, and API SL, SJ, and SH.