Federal Acquisition Savings Act of 2018 This bill requires executive branch agencies to acquire equipment using the method of acquisition most advantageous to the federal government based on a case-by-case analysis of comparative costs and other factors. The methods of acquisition compared in the analysis must, at a minimum, include purchase, short-term rental or lease, long-term rental or lease, interagency acquisition, and acquisition agreements with a state or a local government. The bill includes exceptions for emergency declarations, major disaster declarations, and other emergency situations.