@Josiah, hehehe..!  that is correct, the default sizes and pressure in on a tag sticker. :-)

 

IMHO, The problems start when :

 

a) Changing RIM size

b) Changing Tyre Profile Size

c) Smooth Ride versus Economy

d) Economy versus safety

e) Safety versus performance

 

And pressure seems to be a crazy topic. How detailed do we get to achieve the correct pressure. Asking local tyre experts, opp tyre importers, has not helped much before. Also, petrol stations tend to give different PSI readings with their pressure facilities which makes it more difficult to know.