Good info sharing, just to add engine operates around 100-120c, so using 0W20 engine oil is recommended according to new research and the latest grade GF-5.
0W20 can bear temperature up to 200-220c, and flow faster to cool down, means weather temperature 30-40c is much lesser than engine operating temperatures.
A mindset plus updates needs to be adopted with current research and change, whether, we are still getting 10 years old car, however, engine oil is upgrading.