I've got a 98 SE with 14's and want to upgrade to bigger rims. At firsdt I was looking at 16's (205/55/16 i think?) but then they look A LOT bigger then the stock size. If I go to 16's will it noticably affect my acceleration or MPG? If so How?

1998 Contour 2.5 Non-SVT (ATX)
SHO Y-Pipe
K&N Drop-in