Yesterday, I took an Uber in a 2012-2014 Camry (4 cylinder) similar to my 2013 Camry. It had 391,000 miles. I asked the driver what he did. He said all he did was change the oil, and that he uses 5w-50 full synthetic oil, because that's what high mileage engines need. Heard some squeaks from the suspension, but the engine ran smooth.
I heard it never makes sense to use anything but the recommended oil, here 0w-20, but seeing a 391,000 mile car that's been in lots of city traffic makes me wonder if it's worth switching to thicker oil after a certain point.
Heavier oil for high mileage is something you do for a car like a 1949 Hudson. On a modern car stick with the manufacturer recommended oil unless you want to risk messing up the variable valve timing.
Don't do it he got lucky
