RonC

Just communicated with a Mobile1 rep. He stated that GM has not decided if 0x40 is warranted in Corvettes other than 2019’s.

RonC

Just communicated with a Mobile1 rep. He stated that GM has not decided if 0x40 is warranted in Corvettes other than 2019’s.

Copy of communication
A lot of the details are still "hazy" here. For one, we're still waiting on clarification whether GM is approving the new oil for all years of the C7, or for all years requiring a Dexos approved oil. We've heard GM reps say both. We do, however, know that on models prior to the 2019 Corvette, Mobil 1 5W-30 can still be used to meet warranty requirements, but for 2019 models, it sounds like the new 0W-40 spec is the ONLY warranty approved oil.

This warranty requirement is the main reason why the new oil is going to the 2019 models first. Owners of previous years have choices which are unavailable the 2019 Corvette owners.

orca1946

What changed in the engine that warrants the 0 - 40 ?

Foosh

Nothing changed, except a more capable oil became available. The engines are identical.
My take-away from the OP's post is classic indecision, and the left hand not knowing what the right hand is doing in a large bureaucracy.

DWS44

It would be interesting if GM decided to deny warranty on someone putting 5W-30 in a 2019, since a vast majority of GM's own dealers still have no access to the new 0W-40, and a large number of them who probably still doesn't even know it exists.

Patman

I wouldn't trust the opinion of some random Mobil 1 representative. Read the below Mobil 1 ad, it should tell us all we need to know. Maybe that representative should read the ad put out by his own company

Patman

And let's look at this logically as well. Why would Mobil 1 create this new oil (which already has a limited market) for GM if it was only going to be warranty approved on 2019s? That would limit the market even smaller than it already is. So you can bet your bottom dollar that GM is going to allow this for warranty purposes on more than just 2019s.

Foosh

Yeah, the more I think about it, the more I'm pretty sure the Mobil 1 rep referred to above is not an informed source and/or they are communicating with uninformed sources at GM, which can't get it's act together either.

onyx_z71

GM LS engines with variable valve timing can be sensitive to oil weights because of the oil operated cam phaser. Perhaps the earlier LT engine can be sensitive to the different weight oil. Just a guess on my part.

Foosh

No, I don't think so, since the Corvette Chief Engineer publicly stated on this forum that the new 0W-40 oil is backward compatible to all LT engines since '14 introduction. Apparently, other parts of the GM bureaucracy have not received that memo.

Basil2000

https://www.corvetteforum.com/forums...fill-0w40.html

Here is your answer from tadge.

sonny615

Just ordered some today from my parts department. Of course it's on back order. Lol Hopefully it shows up soon.

BJ67

Same exact engine's in the 2019's except for the LT5. So whats good for the 2019's has to be good for 14, 15, 16, 17, 18.

rmorin1249

What a fiasco.

buckeye4

I would guess it's best to rely on what GM says about warranty oil issues.

madrob2020

Are you trying to say "not covered by warranty" or "not warranted" (to give adequate ground or reason for)? 2nd post here, or I, read OP wrong.

AORoads

I'd wait for GM to decide and give the final word. I can't however imagine what the engine build difference is between a '19 and a pre-'19 Stingray/Z/GS.

madrob2020

Just noticed, there is a longer (more posts), more detailed explanation on Z06 forum.

Brubie

Just had mine in for yearly inspection and oil change on 4-5-18 and they put the 0-40 in. The cost was 11.32 and before paid 10.62 for the 5-30 a quart. Have a 2014.

Foosh

I wouldn't call it a fiasco. I'd call it relatively normal in a big bureaucracy, part of which is an independent dealer network. You should know, Colonel.

It will all get worked out in a few months, and 0W-40 will be clarified as good for all.