Short answer
Cummins Engineering Standard (CES) 20086 is Cummins’ engine oil specification built on API CK-4, and it succeeds CES 20081 (the CJ-4-era standard). Cummins recommends CES 20086 anywhere CES 20081 was previously recommended. CES 20087 is the matching FA-4-based standard, which Cummins says is not backward compatible and should be used only when the owner’s manual directs.
How Cummins oil standards line up with API
Cummins publishes its own engine oil standards and maps them to API categories. CES 20081 corresponds to API CJ-4, CES 20086 to API CK-4 and CES 20087 to API FA-4.
Cummins’ standards add requirements beyond the API category. Industry summaries of CES 20086 list limits such as sulfated ash no higher than 1.0 percent and a minimum HTHS viscosity of 3.5 cP, which track the CK-4 chemistry and viscosity framework.
Where CES 20086 applies
Cummins states that CES 20086 oil can be used where CES 20081 was recommended and in diesel engines running on ultra-low sulfur diesel fuel. That makes it the default for many on-highway, pickup and off-highway Cummins engines.
Cummins engines in pickups, such as the Ram 6.7L, may also carry vehicle maker requirements, so read both the engine and truck documentation.
CES 20087 and FA-4
CES 20087 covers the lower-HTHS FA-4 category. Cummins has said FA-4 oils are not backward compatible and should be used only where the owner’s manual calls for them.
In practice that means CES 20087 oils are limited to specific newer engines designed for them, and are not a general substitute for CES 20086.
Verifying an oil
Cummins registers oils that meet its standards. Look for the exact CES number on the oil’s current data or label, and check the Cummins owner’s manual or Cummins’ engine oil recommendations bulletin for your engine.
Viscosity still matters. CES 20086 oils come in grades such as 15W-40, 10W-30 and 5W-40, and Cummins’ temperature guidance determines which grade suits your conditions.
Frequently asked questions
Does CES 20086 replace CES 20081?
Yes. Cummins recommends CES 20086 oils anywhere CES 20081 was previously recommended.
Can I use a CES 20087 oil in an older Cummins?
Cummins says FA-4 (CES 20087) oils are not backward compatible. Use them only when the owner’s manual says to.
General maintenance information. Always follow your vehicle or equipment manufacturer’s requirements and the current product data. Questions? Email [email protected].
