This report describes the results of testing the 'FUEL-MAX' device as part of an evaluation under Section 511 of the Motor Vehicle Information and Cost Savings Act. The FUEL-MAX is an air-bleed device which replaces a vehicle's Exhaust Gas Recirculation (EGR) valve. The amount of air bled into the intake manifold is determined by the vacuum signal which once controlled the action of the EGR valve. This device is claimed to conserve fuel. The primary purpose of this project was to evaluate the effect of the FUEL-MAX on exhaust emissions and fuel economy. Testing of three typical 1979 model year passenger cars was conducted during March, 1981. The basic test sequence included the Federal Test Procedure (FTP) and the Highway Fuel Economy Test (HFET). These tests were performed both before and after installation of the FUEL-MAX. As a result of the testing, average hydrocarbon and carbon monoxide emissions decreased somewhat while oxides of nitrogen displayed substantial increases. Fuel economy was found to increase approximately three percent on the FTP but exhibited no change over the HFET. The occurrence of engine knock was obvious on two of three vehicles. EPA's Office of Enforcement has determined that the FUEL-MAX can violate the anti-tampering provisions of the Clean Air Act.