@@岡田卓也-j6y I'm in the same situation. I came to the conclusion in the hot summer months I use 5w-30 and wintertime 0w-30. In the end I will run Ow-30 year round. At least here in the Nagasaki area. winters are mild and summers are hot & humid.
Toyota walks a fine line between fuel economy and engine wear. By placing the 0w-16 and 0w-20 at the top recommended oil choices in the owners manual. When in fact it is better to run a 5W-30 in the summer months and a 0W-20 in the winter. Toyota's game is, the faster your engine wears out, the faster you buy a new car. :(