GM DexosR site changes again

[redhat]

Well that was short lived, Mobil 1 FS Euro 0W-40 is now gone from the DexosR GM page, as is the Mobil 1 ESP 0W-40 entry. What remains is Mobil 1 Supercar 0W-40 and 5W-50 along with three new entries.

Castrol EDGE M 0W-40
and Pennzoil Ultra Platinum 0W-40 API SP and SQ

Not that I throw a ton of weight in this but it's interesting. Maybe aligning with the nuanced "back and forth" recall language of the L87?

 

[PontiacHO]

You’ve hit the nail on the head. Yes, it’s changed again after GM now realizes that their engines fail because of the production issues, not the incorrect oil.

 

[4wd]

Being it was intended for sports cars to start with …

 

[fantastic]

Here's some more conversation about it...

R

Thread 'Mobil 1 Full Synthetic 0W-40 and Mobil 1 ESP X4 removed from dexosR licensed list'

Dec 26, 2025

Does anyone know why the Mobil 1 Full Synthetic 0W-40 and Mobil 1 ESP X4 was removed from dexosR licensed list? Is it a mistake? Were they reformulated? Did GM discover it didn't meet the requirements?
https://www.gmdexos.com/brands/dexosr/index.html
The product data sheets still list them as dexosR approved.

It is very strange that GM dexos could remove oils once they have been approved.

• RKCRLR

• 

 

[Selmorides]

I wonder if the new Pennzoil bottles will still have the SRT logo on it. Would you use this in a Gen 1 Chevy small block with a roller cam?

 

[sw91]

Has anyone ever seen this Edge 0w-40M? It's on the product list on the Castrol website (with a Dexos R logo on it), but I don't see it sold anywhere.

 

[IndyFan]

You’ve hit the nail on the head. Yes, it’s changed again after GM now realizes that their engines fail because of the production issues, not the incorrect oil.

They knew that all along. The 40 weight oil was to prevent further loss. A band aid of sorts. But they knew what the problem was, I would bet very quickly.

I think they are fine tuning the spec and stabilize it so other oil companies can get the certification. I´d guess Mobil 1´s marketing adjusted to this, too. They helped GM out quickly, but now that it´s stabilized, they know what oil they want Corvette owners using. Supercar appears to be marketed above the other 0w40´s, and is priced accordingly. So leave it with the designations and withdraw the others.

That´s my best guess.

 

[k1xv]

Whatever happened to the good old days when almost any vehicle could get by on any brand of HD 10w-30?

 

[Gyro Gearloose]

With a few hundred thousand cars suddenly added to the user list I wish WM would take note and stock even one of the choices.

 

[Z28racecar]

I wonder if the new Pennzoil bottles will still have the SRT logo on it. Would you use this in a Gen 1 Chevy small block with a roller cam?

If your bearing clearances and operating temperature range call for a 40 grade, it's not a big deal

 

[IndyFan]

Whatever happened to the good old days when almost any vehicle could get by on any brand of HD 10w-30?

I remember those days! They ran great until about 100k and then began laying down smoke screens like a WW2 destroyer hiding a Liberty Ship convoy. Except for Volvos. Those old 240's ran forever!

 

[CleanSump]

I remember those days! They ran great until about 100k and then began laying down smoke screens like a WW2 destroyer hiding a Liberty Ship convoy. Except for Volvos. Those old 240's ran forever!

Yeah, rings or valve guides gone somewhere after 60k miles.

 

[colloyd00]

What happens to the licenses that were used to approve FS/ESP X4 as Dexos R compliant? Thanks to @Glenda W. for the screenshot here https://bobistheoilguy.com/forums/threads/new-mobil-1-advanced-clean.400542/page-6#post-7395824

Are those Dexos licenses "revoked"? "Expired"?