Oil - going from 0w20 to 0w40

[Maximus Gladius]

but this will not be settled until I contact Jeep

It may not be settled even if you contact them. You’re expecting a lot, even to think they’ve read their own published material. The manuals are for the vehicle own to interpret. Want to see the author short circuit, ask them to clarify what they write.

The scariest thing a dealership experiences is a vehicle owner walking in with the book and being asked to clarify or explain in detail fashion some ambiguity in the book. I tried that once. Even had a meeting with the GM of one fine Chrysler dealership to have him explain something in the book. He said to me, in his very advanced way of clarifying my question,… “I haven’t read the manual and I’m not about to start. Get out of my building”. …and I never went back and never will.

If you come at them with the way you do that is very precise and analytical that backs your question, you will short circuit them. You must dumb down your approach and not make their job hard.

Good luck! (Would love to be a fly on the wall of the poor sap that gets your email)

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[g2020]

It may not be settled even if you contact them. You’re expecting a lot, even to think they’ve read their own published material. The manuals are for the vehicle own to interpret. Want to see the author short circuit, ask them to clarify what they write.

The scariest thing a dealership experiences is a vehicle owner walking in with the book and being asked to clarify or explain in detail fashion some ambiguity in the book. I tried that once. Even had a meeting with the GM of one fine Chrysler dealership to have him explain something in the book. He said to me, in his very advanced way of clarifying my question,… “I haven’t read the manual and I’m not about to start. Get out of my building”. …and I never went back and never will.

If you come at them with the way you do that is very precise and analytical that backs your question, you will short circuit them. You must dumb down your approach and not make their job hard.

Good luck! (Would love to be a fly on the wall of the poor sap that gets your email)

I'd like to talk to ultimate approver of the copy for the revisions to the online version of the 2020 owner's manual. Then I might learn whether this is Jeep's way of pulling a Houdini and escaping from the CAFE straightjacket.

 

[Maximus Gladius]

I'd like to talk to ultimate approver of the copy for the revisions to the online version of the 2020 owner's manual. Then I might learn that this is Jeep's way of pulling a Houdini and escaping from the CAFE straightjacket.

If anyone will find this individual, it’s you. Holding my breath….

 

[Hootbro]

It is obvious that I believe this is more than just a list of grades that API certifies. If they were going to stick exclusively to 0W-20, they would not have revised the 2020 owner's manual. Also, if this were just a list of grades that API certifies, they would not have omitted 5W-20 and 10W-30 from the 2026 owner's manual. The starburst is still right there on the front label of Mobil 1 EP 5W-20.

Also see the justification in a different post. This information has been out there for more than a year.

In all cases, 0W-20 is still recommended.

I will not consider this to be settled until I contact Jeep.

I think you are projecting something that is just not there and is basically a change of their boiler plate ad copy in the owners manual. I looked through all years of the JT OM's and it seemed to switch in 2022 to the three listed grades with 2021 and prior having the five listed grades.

For point of referenced, since I have owned a 2018 RAM 2500, I checked their owners manual and they had the same switch over from 5 grades listed in 2021 and prior, and then changed to 3 grades listed for the API Starburst symbol for 2022 through current 2026.

If I followed your logic from my 2018 RAM 2500 owners manual, I could theoretically run 0W-20 without consequence in my 6.4L HEMI that calls for 0W-40 as "recommended" which I highly doubt is the case.

 

[g2020]

I think you are projecting something that is just not there and is basically a change of their boiler plate ad copy in the owners manual. I looked through all years of the JT OM's and it seemed to switch in 2022 to the three listed grades with 2021 and prior having the five listed grades.

For point of referenced, since I have owned a 2018 RAM 2500, I checked their owners manual and they had the same switch over from 5 grades listed in 2021 and prior, and then changed to 3 grades listed for the API Starburst symbol for 2022 through current 2026.

If I followed your logic from my 2018 RAM 2500 owners manual, I could theoretically run 0W-20 without consequence in my 6.4L HEMI that calls for 0W-40 as "recommended" which I highly doubt is the case.

Here's the copyright (2022) & version on the last page of the 2020 manual that I downloaded in April 2025.

This at least narrows the reason for the revisions. I said that this was the result of loosening CAFE standards. Google AI said that these changes were related to improvements in preignition, but then Google AI admitted that it was hallucinating (I always ask).

It would be interesting to know when the printed manuals started listing additional grades or grades that API certifies. I know that they didn't start doing this until after September 2019.

If I haven't already done so, I will add some comments in my recent posts to make sure people know this is not settled.

 

[Jrgunn5150]

Lol

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