OP increased drag, which will effect acceleration and mpg.
Even if the wheels and tires are only X amount heavier, the tire is taller, which will reduce aerodynamics and add drag/ turbulence. Same goes for lifting. You are presenting a taller, less aerodynamic shape to the wind.
It will be noticeable in small amounts, maybe a few percentage points of acceleration and mpg.
This is the same principle of going from a stock Sport S bumper, with the attachments that go to the fender, to a stubby bumper. Your MPG will drop.