In order to meet the U.S. emission standards, most motor vehicle manufacturers have chosen to use the technology of, and related to, the three-way catalyst. In Canada, the emission standards are less stringent which has allowed some manufacturers for 1981 vehicles to adapt U.S. technology to be compatible with Canadian requirements. To meet these requirements, two approaches are currently being used; oxidation catalyst and non-catalyst lean burn.The purpose of this program was to evaluate, on a comparative basis the emissions, fuel consumption, performance and driveability of four similar matched pairs of North American vehicles with U.S. and Canadian emission control systems.The results confirmed that exhaust emissions at FTP temperatures were lowest with the U.S. 3-way catalyst technology. This advantage over the oxidation catalyst and lead tolerant technologies was somewhat reduced at cold test temperatures. There was little difference between the fuel consumption, performance, and driveability of Canadian and U.S. specification vehicles under the test conditions investigated.