July 13, 2005 – Federal Register Recent Federal Regulation Documents

This regulation revises and harmonizes test procedures from the various EPA programs for controlling engine emissions. It does not change emission standards, nor is it intended to change the emission reductions expected from these EPA programs. Rather, it amends the regulations that describe laboratory specifications for equipment and test fuels, instructions for preparing engines and running tests, calculations for determining final emission levels from measured values, and instructions for running emission tests using portable measurement devices outside the laboratory. These updated testing regulations currently apply to land-based nonroad diesel engines, land- based nonroad spark-ignition engines over 19 kilowatts, and recreational vehicles. The revisions in this final rule will update the regulations to deal more effectively with the more stringent standards recently promulgated by EPA and will also clarify and better define certain elements of the required test procedures. In particular, the amendments better specify the procedures applicable to field testing under the regulations. This action also applies the updated testing regulations to highway heavy-duty diesel engine regulations. This action is appropriate because EPA has historically drafted a full set of testing specifications for each vehicle or engine category subject to emission standards as each program was developed over the past three decades. This patchwork approach has led to some variation in test parameters across programs, which we hope to address by adopting a common set of test requirements. The primary goal of this effort is to create unified testing requirements for all engines, which when implemented will streamline laboratory efforts for EPA and industry. This action will also include other technical changes intended to clarify and better define requirements for several different EPA engine programs. These changes are relatively minor and are technical in scope.