Oil return ports

This is published test data for a major synthetic brand of oil. Royal-Purple-HPS-PDS-06July2021-1.pdf (royalpurple.com)
See table below.

I've highlighted a couple of test points I believe are very relevant here.
--------------
HTHS @ 150C, cP ==> High Temperature, High Shear viscosity as measured in centipoise or cP units @ 150C (302F). That is H-O-T. Nobody is running their oil this hot. Not in a 3rd gen Tacoma.

Notice the 5W20 oil has a HTHS viscosity of 2.7 cP. (Water is 1.0 for reference). Meanwhile, the 20W50 oil has a viscosity if 5.2. That means the 20W50 oil has almost twice the resistant to flow. Why would you want to use an oil that has twice the resistance to flow?

Unless you have an engine that was built with looser tolerances (typically much older or very worn engines) and you are trying to minimize oil "blow by" by way of oil type, then this does not apply here.
-----------------
Flash Point, C (F)
This is the chemical temperature at which a liquid begins vaporizing such that the vapors can ignite. In other words, this a measure at which the oil begins to degrade chemically.

Note the 5W20 has a flash point of 420F while the 20W50 has a flash point of 436. That's only a 4% difference and is irrelevant at ordinary engine temps. See above. Nobody here is running their oil temp that hot.

In other words, the 5W20 oil is going to hold up just as well as a 20W50 oil while (see above) offering HALF the flow resistance.



ENGINE OIL MANUFACTURERS HAVE CONDUCTED MILLIONS (IF NOT BILLIONS) OF DOLLARS OF RESEARCH TO PROVIDE TO THE CONSURMER MARKET ENGINE OILS THAT ARE THIN, EASY TO FLOW (PUMP) AND YET ALSO RESISTANT TO HIGH TEMPERATURE BREAKDOWN.

This is the key point here.

Run the light oil. They are good and good for your engine

 

I am certainly ignorant of these modern engines , I am a pre vortec chevy guy and am always willing to learn , All the points people have made other than the port size were things I had not considered . I was worried about the oil sheer and breaking down the oil on extra hot pistons and losing protection for the bottom end . Years ago when towing heavy with a small block Chevy " 350 with the 383 kit " I could watch thermal runaway happen if I was lugging it a little going over the pass . The coolant temp would rise maybe 15 deg above normal and the oil pressure would start dropping , sometimes 20 lbs if I wasn't watching close enough . Had to put a oil cooler on it and use less throttle . I would have never imagined it would happen so easily if I hadn't had it happen so frequently , I would make fresh oil turn as black as could be and smell burnt , Changed oil at the campground a few times before I got it sorted out . ( I had to take the engine builder for a long ride to show him because he didn't believe me )
I will run the suggested heavier weight oil per the manufacturer .
I just don't want to kill the engine because of lubrication failure .
I am also looking into which app and dongle to monitor trans temp .

 

This engine won’t put out enough power to pull heavy enough load to do that to the engine.

 

[sigh, agreed}

Which begs the question to the OP? Why run the heavier oil?!?!!

Run the LIGHTER OIL dude.

 

I would rather ask the question than just use the heavier oil and wish I hadn't . There have been many good valuable responses to my question that I had not considered . I will not be using 20-50 and I'm glad I asked my stupid question . This extra knowledge and input will come in handy . Variable valve timing complications was certainly something that never crossed my mind .

 

If you wana know more than you ever wanted to know about oil check this guy out.

https://www.youtube.com/@themotoroilgeek

 

Ok. But the owners manual and that information sheet for the engine are not consistent.

 

The only problem I've had is trans temperature at very low speeds on steep hills. There wasn't enough air flow to cool the fan-less trans cooler.