just to add on, usually 5w-50 viscosity oils are protective in nature so they keep engine working at an optimum level through its life cycle and prevent damage during high stress.
if you look at the boxes of 5w-50 oils (may it be any manufacturer) it says max protection usually.
5w-20, 5w-30 are more suited to better fuel economy.
5w-40 is a premium range and mostly fully synthetics lie or cover this range.
5w-50 are mostly most expensive due to higher content of additives to achieve high working range.
