Ford Motor Co. said the Environmental Protection Agency may change its procedures for testing the mileage of hybrids. Several of Toyota Prius hybrid models showed even bigger fuel-economy shortfalls against the EPA estimates than the Ford Fusion hybrid and C-Max hybrid when tested for mileage in city driving by Consumer Reports magazine, Raj Nair, Ford’s product development chief, said in light of criticism Ford has taken lately for possibly overstating mileage.