This report presents the manufacturing costs of emission control technology used to meet recent U.S. and European emission standards for heavy-duty diesel engines and vehicles. The costs assessed include both the in-cylinder technologies to control engine-out emissions and the after treatment technologies that act on the exhaust stream. With the benefit of hindsight, this report focuses on the primary technology pathway that was or is in widespread commercial use, to provide reasonable cost estimates for the increasingly sophisticated technology packages used in each regulatory stage.