20s= bigger, more expensive wheels, most of the time better looking cuz its bigger , bumpier/stiffer ride, most of the 20" wheel set ups will make ur car handle better, most likely wont fit snow tires


19= smoother ride, cheaper tire replacements, and a possibility to rotate ur tires if set up is not staggered, possibility of putting on snow tires, cheaper wheels overall cuz of size

__________________