OVERKILL
$100 Site Donor 2021
I'd say 0w-40 has about twice the viscosity of 0w-20 anywhere in the temperature range
Not when you get really cold, down near where CCS is measured typically. Look at how close all these oils are for example, only the 0w-8 is ~50% thinner:
Then compare to M1 0w-40 versions, which actually have a lower CCS visc: