Correct. Both specs are in the early 2020 manuals. Apparently that was in error and the old spec should have been removed. If you download the manual today only the new spec is mentioned. If you go to the dealer, only the new oil will be used which is why oil changes are so expensive.I am not sure what spec you are referring to but they specifically recommend Rotella T6 in the owners manual.
Here's a little more info:
I have a 2020 Ram 1500 with the new Gen 3 EcoDiesel engine. The owners manual is contradictory, and I want you guys' opinions on this. Page 369 states, "The manufacturer recommends engine oils that meet the requirements of FCA Material Standard MS-10902, and that are API CJ-4 certified." On...
Also, Ram representatives on other forums have confirmed that MS-12991 is the only oil spec for Gen 3 engines.