Not to mention Ford, Toyota, Honda and Subaru all specify 0W-20 and I don't hear of any massive engine recalls from them that could be construed as "oil related".....
Those are good discussion points.
When an engine, or specifically a rotor system with hydrodynamic bearings, is designed with 0w20 as the primary oil then it can work. If you set your viscosity to a 0w-20, then design the bearing width, diameter, and clearance to support a good eccentricity ratio, then it will work. further, you can even see how low the viscosity can drop before the eccentricity ratio gets into a danger zone.
Victor Sheppard took 2 toyota engines to 1 million miles using 0w20 and 10,000 mile oil change intervals.
Longtime Toyota truck owner Victor Shepherd drives an average of 10,000 miles a month.
www.thedrive.com
And yeah lots of highway miles but hot shot drivers also get a lot of idling time waiting to be loaded up...
Toyota's V35A-FTS recall on the new 3rd gen was, according to them, debris related. It wasn't every single v6 either-- the Lexus GX 550 wasn't in the recall despite having same basic engine (different turbo and induction system).
Looking at the failed bearings it didn't look like debris was the issue. And how debris "shows up" as a failure in trucks with 46,000 (or more) miles is a painful stretch of credibility. I'm sure debris was an issue but not the whole story.
The failed bearings appeared to show an overload condition from too little clearance: a shifting main cap ("cap walk" on forced induction engines is a thing) or the main cap jaw fits being too tight or too loose. The main bearing cap design and the main cap girdle/web stiffener was changed from original 2018 Lexus design.
Could 0w20, especially a fuel diluted oil, be a major contributor? sure. But the original V35A never had the bearing problem even using 0w20 which it was designed for. And I'm sure there were plenty of lazy LS 500 owners who justified 10,000 mile oci's while taking short trips and idling extensively outside of Whole Foods...meaning plenty of cases of fuel diluted engine oils...
The problem popped up when the main cap and girdle design changed.
And it is known that the GX 550 has a different main bearing part number than what is in Tundra or Lexus LX600. The GX 550 never had this issue.
Regardless...Toyota stomped that problem out fast and it didn't involve changing oil spec.
The bottom end of the 6.2 and 5.3 haven't materially changed since their inception as an LS1 engine. But what has changed is getting cute with 0w20.
If an engine was designed originally for 0w20 you can be reasonably sure it is good to go. If an engine was designed for a higher viscosity oil and suddenly, and with no clear design change to support it, drops the viscosity down a few grades, while increasing specific power output from engine, then red flags should be going up.