Control of Emissions of Air Pollution from 2004 and Later Model Year Heavy-Duty Highway Engines and Vehicles; Revision of Light-Duty On-Board Diagnostics Requirements

概要

Today's action finalizes a major new program to reduce emissions from on-highway heavy-duty engines and vehicles. These reductions will provide for cleaner air and greater public health protection, primarily by reducing ozone pollution. This program is the first phase of a multi-phase strategy to reduce emissions from heavy- duty engines and vehicles. A key element of this action is a reaffirmation of the technical and economic feasibility of the non-methane hydrocarbon plus nitrogen oxide (NMHC+NO X ) standard promulgated in October, 1997 for diesel heavy-duty engines. This previously-codified standard will therefore remain unchanged and effective starting with the 2004 model year for heavy-duty diesel engines. This standard represents about a 50 percent reduction in emissions of nitrogen oxides, as well as reductions in hydrocarbons, from diesel trucks and buses. Heavy-duty diesel engines and vehicles will also be subject to new test procedures and associated requirements beginning in the 2007 model year that will ensure that emission standards are met across a broad range of engine operating conditions. In addition, this action puts in place new more stringent emission standards