Talking commuter bike: My Nokian W106 max sidewall rating is 65psi, That's where I run them when it's dry which is a lot of days in the winter. There may be small patches of ice which never go away all season but the studs still work fine, It helps a bit to decrease overall rolling resistance. But in real wintery icy conditions with lots of ice I'll run them at 35-45psi. The lower pressures really make grip improve due to a bigger contact patch and more give in the sidewalls. Of course they are slower on the dry parts, but that is the tradeoff.