Tires: how exact need to be?, nitrogen molecules, exact need

Question
I try to keep 32psi in my vehicle's tires and sometimes agonize over making sure that each tire has EXACTLY that amount, it's a real pain. But how much difference in psi can there actually be amongst the 4 tires without it being a concern, as far as them wearing unevenly, etc.? Thanks

Answer
Hmmmmm, well, this question is more involved than you may think.

For example: as little as 2psi difference can generate or correct a slight pull/push in steering.  Personally I try to keep all my tires within 2psi of one another.

A consideration here may be for you to look into Nitrogen fill.  Slightly expensive but, if you have an agonizing concern as you indicated then this may be your answer.  Nitrogen doesn't seep from tires as air will thus providing sustained and uniform tire PSI. Nitrogen molecules are larger and do not expand as much when heated.  You should be able to find this service at most of the Company or Chain stores.