Oil weight for 5.3? 0-20 no good?

[jerry455]

I have been running 0W30 in my 2021 6.2 Suburban for quite a while now with no problems.

 

[DuraYuk]

Boom.

https://gmauthority.com/blog/2025/05/should-you-use-0w-40-oil-in-your-non-recalled-gm-6-2l-l87-engine/

 

[Gearz]

5W-30 End of story. All these years we were told not to change the viscosity and guess what it was a LIE. Small changes are fine just don't use a 10W-50 in a 0W-20 engine. It's all so the manufacture can squeeze out the mileage criteria! I worked for a dealer on the line for 30 plus years and we never did a oil analysis to see if the correct oil weight was used!

 

[vcode]

5W-30 End of story. All these years we were told not to change the viscosity and guess what it was a LIE. Small changes are fine just don't use a 10W-50 in a 0W-20 engine. It's all so the manufacture can squeeze out the mileage criteria! I worked for a dealer on the line for 30 plus years and we never did a oil analysis to see if the correct oil weight was used!

Yet there are millions of 5.3L's out there that have traveled billions of miles on 0W20 with no issues. Go figure......

 

[viven44]

I think on a 5.3L we are talking about 200K+ miles with 0W-20 vs 300K+ with 5W-30.

Either option will obviously work and get a lot of miles, but it doesn’t change the fact that 5W-30 in GMs own words on oil viscosity that a thicker oil will offer “an enhanced further level of protection” than 0W-20.