Oil Weight Recommendation after GM engine recall

[Balsa]

GM recently posted an engine recall because their recommended oil weight of 0W-20 is too thin to adequately protect the engine. They changed their recommended oil weight to 0W-40. In short, heavier weight oil increases the thickness of the oil film on rod bearing reducing the risk of galling under high loads. The actual situation is more complicated. The Motor Oil Geek goes into more detail on Youtube.

So...Is the recommended 0W-20 the best oil choice for engine longevity or was the weight chosen to increase fuel economy?

Please post a response if you know the what the Tundra's owner's manual recommends for oil weight? - I assume that Tundra, with the same engine, would be considered a heavy duty application vs the GX.

What do the owner's manuals recommend for the GX in Australia or other international location? - Assuming that Australia does not have to comply with USA CAFE standards, so fuel economy would be less of a consideration in the oil weight recommendation.

Toyota's quality has always been better than GM, so I'm inclined to trust Toyota's oil weight recommendation, but I'd still like to know if there is any difference in recommendations in the various applications of this engine.

 

[A10MileHusker]

Here is some quick info I found online regarding US vs AU fluids.

US:

AU:

 

[Balsa]

Thanks A10MileHusker. I found the 2025 USA Tundra and 2025 Australia GX owners manuals. These both listed 0W-20 as the recommend oil. The note, "This viscosity prescription is for the USA market only; a wider range of viscosities is allowed for other markets." suggest that 0W-20 is the balance point of fuel efficiency and protection. The AU alternatives are only a 30 weight oil, so the alternative recommendations are not a major swings in viscosity.