Well recently I’ve got to known to the fact that weather does matters.
Because if Car is produced in Japan, then they will recommend 0w-20
If same car is export to Europe, then oil recommendation will be same.
If Japanese export same car to Pak/India, then they will recommend 10w-30 or 5w-40
If they export same car to countries who have more hot weathers like Sudan, Nigeria, etc., then they will recommend 10w-40 or 20w-50
Hence, for Pak. in summer/winter, i think 5w-30 or 5w-40 would do best for all year round use.
Lets say what other experts say.