Oil weight for 5.3? 0-20 no good?

[Antonm]

So in your opinion thicker liquid flows just as fast as thin liquid?

No, it’s not an opinion, it’s just physics.

Positive displacement pumps ( like most automotive oil pumps are) pump the same volume of fluid per revolution regardless of fluid viscosity.

Yes pressure will be higher and it’ll take more power to turn the pump, but it’ll put out the same volume of fluid with either weight oil.
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[vcode]

Found this bulletin from 2013, it sure looks like GM made a big push for 0W-20 back then for 2014 year models

https://static.nhtsa.gov/odi/tsbs/2013/MC-10246634-9999.pdf

saying that apparently

"These engines utilize an advanced combustion system that maximizes the potential of the direct injection (DI) fuel system, active fuel management (AFM), variable valve timing (VVT), two stage oil pumps and other technologies. The dexos1™ 0W20 oil supports these technologies"

but they sure have walked back in the face of the recall and saying 0W-40 is better in the suspect engines (I doubt they have volume reliability data to back that up, this doing so must fundamentally suggest that they believe 0W-40 is better on the 6.2L and has the best chance of taking those engines to the "finish line" despite the use of all these awesome fuel savings technologies like DFM, DI)

More from the bulletin.
Question: Can another oil such as 5W30 that is cheaper and more widely available be used in place of dexos1™ 0W20oil?

Answer: No. The 5.3L and 6.2LV8 EcoTec3 engines available in the 2014 Silverado 1500 and Sierra 1500 pickup trucks were designed, engineered and validated to run using dexos1™ 0W20 oil. This is the ONLYoil approved for these engines.

Needing more comparative data will take years and unfortunately not be possible if everyone keeps using 0W-20. All we know is the GMT800/900 engines easily went to 300K on 5W-30. How many 200K engines have we seen here on 2015+ year models ? It’s gonna take more years to see how reliable these are. Our 2018 Tahoe sure started having some problems around the 90K mark.. oil burning, intermittent blinking misfire CELs after long trips, etc

So this is only a guess..... but I would think that 0w20 full synthetic is at least as good, if not better than the 5W30 dino used in my 2010 Tahoe. Oil has come a long way since then and it takes a pretty good base stock to make a 0W anything oil.

 

[GMCChevy]

No, I just checked an auction I have membership at; there are plenty of 200K+ mile trucks listed there 2014 and newer with very few having mechanical faults so I have no doubts the 0W-20 can take it past 200K..... interestingly 5.3L to 6.2L showing up at a 25:1 ratio for 200K+ mile ones, and at a 12:1 ratio for <100K mile ones....

I'm guessing that's probably also close to the ratio of the number of trucks with the different engines since most purchasers wouldn't pay more for the bigger engine and if they needed more they'd go diesel.