Can anyone tell me about the alphabet soup I find on the oil?

I did a little looking in my manual and googling and found that I should use 15W40 API Cl-4/SH with less than 1.85 mass % sulfated ash....

ok, the 15W40 part I understand.

I learned that the Cxxx API specs are for "Commercial" and applicable to diesel. The "Sx" specs are for gas.

So I go to pick up some oil and find Rotella T promising low soot and Cummins CES20078, 20077, 20076, 20071 and
API Cl-4/SJ, SL.

Can I ignore the SJ, SL part and not be concerned it's not SH?

What's the CES part? (not mentioned in my owners manual)

No notes about sulfated ash...

I bought it, I hope it's ok to use it.

 

Rotella T is fine. I've been running it for almost 40K miles and knock on wood, I haven't had a single problem.

 

As long as it's the right weight and it says CI-4 on the bottle, it's OK.

 

if you are talking about the CI or SG ratings, the C is for compression ignition and the S is for spark ignition