Every shoe is different; certain shoes, like athletic shoes, will mold to your foot type (wide, narrow, etc) can mold to the shoe shape giving it a perfect fit It depends on the shoes and your feet, I say try them on and see how they feel
To be honest you will get your foot in those....its only .5 of a difference....however expect some tightness a little....Shoe companies are different in sizing..............For the record.....170 for shoes your going to walk in on the dirty ground.......Welcome to America.