Designed for 0w-20 but 5w-30 is recommended?

[Bill7]

I recently bought a 23 Colorado ZR2 which has the 2.7L Turbo engine and did a bit of research on the engine before purchase. So far I'm impressed with the engine.

I was watching a YT video of an interview with one of the GM engineers that developed the engine. One of the comments he made was that the engine was designed to run on 0w-20 oil but they recommend 5w-30 for increased protection and longevity. I thought that was interesting and it goes along with my general thoughts on oil viscosity.

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Even though my vehicles are speced for 20 weight oils, I only use 5W-30 due to the higher High Temperature High Sheer (HTHS). I am very happy with my choice. I haven't bought any 20 weight oil in over 3 years (and it feels good).

 

[SubieRubyRoo]

Omg, omg, OMG!

He said it out loud!

CAFE police are gonna come and git that Gee Eminem injuneer and carry him away!
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Luchansky: "So just provides a little more, a little bit more resistance, uh, you know, a little better capability for the bearings"
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Yep, I wanna some mo' 'o that re-zis-tents !

Sock it to me!

Not just some re-zis-tents, it’s the whole village:

 

[Brons2]

Even though my vehicles are speced for 20 weight oils, I only use 5W-30 due to the higher High Temperature High Sheer (HTHS). I am very happy with my choice. I haven't bought any 20 weight oil in over 3 years (and it feels good).

I haven't bought any oil since 2017, just been working off my stash.

And to make it more topical, I just finished the last of the Xw20 in my stash at the Outlander's last OCI. I figure, I will run the most shear prone 5w30 in it that I have in my stash. It's got 77K now, I ain't skeered!

 

[Kestas]

... the engine was designed to run on 0w-20 oil but they recommend 5w-30 for increased protection and longevity.

I'm guessing this is a CAFE driven statement. If I read between the lines correctly, they qualified the engine to run on 0W-20, but admit that 5W-30 is better for the engine. CAFE numbers are gathered using the fluids used to produce the vehicle for sale, in this case 0W-20. Their wording is used to satisfy both CAFE and the people who actually care for their vehicles.