UNINTENDED CONSEQUENCES: Why CAFE changes could lead to larger cars, not smaller ones. “A study by the University of Michigan shows that auto manufacturers could meet tougher fuel economy standards simply by increasing the size of the vehicles they sell. A ‘footprint-based’ formula for calculating mileage targets was adopted when Corporate Average Fuel Economy standards were revised in 2007. Researchers now think this could lead to bigger vehicles on the road rather than increases in fuel economy for our nation’s fleet.”