This paper summarizes a laboratory effort toward reducing nine-mode cycle composite emissions and fuel consumption in a heavy-duty gasoline engine, while retaining current durability performance. Evaluations involved standard carburetors, a Dresserator inductor, a Bendix electronic fuel injection system, exhaust manifold thermal reactors, and exhaust gas recirculation, along with other components and engine operating parameters. A system consisting of electronic fuel injection, thermal reactors with air injection and exhaust gas recirculation, was assembled which met specified project goals. An oxidation catalyst was included as an add-on during the service accumulation demonstration. In addition, the driveability of this engine configuration was demonstrated.