Does "Pixels to Units" on importing assets affect performance?

Does it make a differene in performance if I make "Pixels to Units" 16 vs 256 on importing? 256 will give me tiny images, and 16 will give me semi normal sized images... does this matter at all to the engine's performance if I zoom the camera in anyway? I will have possibly 1000's of 16px by 16px tiles, but if it's all the same for performance I'll go with a smaller "Pixels to Units" setting to keep my physics straight and my camera not zoomed in all the way.

Any input is appreciated, thanks.