The Environmental Protection Agency (EPA) and the National Highway Traffic Safety Administration (NHTSA) have issued a notice of proposed rulemaking (NPRM) to establish a comprehensive Phase 2 Heavy Duty (HD) National Program that will reduce greenhouse gas (GHG) emissions and fuel consumption for new on-road heavy duty vehicles. This technology-advancing program would phase in over the long-term, beginning in the 2018 model year and culminating in standards for model year 2027, responding to the President's directive on Feb. 18, 2014, to develop new standards that will take us well into the next decade. NHTSA's proposed fuel consumption standards and EPA's proposed carbon dioxide (CO2) emission standards are tailored to each of four regulatory categories of heavy duty vehicles: Combination tractors; trailers used in combination with those tractors; heavy duty pickup trucks and vans; and vocational vehicles.
The proposal also includes separate standards for the engines that power combination tractors and vocational vehicles. Certain proposed requirements for control of GHG emissions are exclusive to EPA programs. These include EPA's proposed hydrofluorocarbon standards to control leakage from air conditioning systems in vocational vehicles, and EPA's proposed nitrous oxide (N2O) and methane (CH4) standards for heavy duty engines. Additionally, NHTSA is addressing misalignment in the Phase 1 standards between EPA and NHTSA to ensure there are no differences in compliance standards between the agencies. In an effort to promote efficiency, the agencies are also proposing to amend their rules to modify reporting requirements, such as the method by which manufacturers submit pre-model, mid-model, and supplemental reports. EPA's proposed HD Phase 2 GHG emission standards are authorized under the Clean Air Act and NHTSA's proposed HD Phase 2 fuel consumption standards authorized under the Energy Independence and Security Act of 2007. These standards would begin with model year 2018 for trailers under EPA standards and 2021 for all of the other heavy duty vehicle and engine categories. As noted, the proposal also includes certain EPA-specific provisions relating to control of emissions of pollutants other than GHGs.
EPA is seeking comment on non-GHG emission standards relating to the use of auxiliary power units installed in tractors. In addition, EPA is proposing to clarify the classification of natural gas engines and other gaseous-fueled heavy-duty engines, and is proposing closed crankcase standards for emissions of all pollutants from natural gas heavy-duty engines. EPA is also proposing technical amendments to EPA rules that apply to emissions of non-GHG pollutants from light duty motor vehicles, marine diesel engines, and other nonroad engines and equipment. Finally, EPA is proposing to require that rebuilt engines installed in new incomplete vehicles meet the emission standards applicable in the year of assembly, including all applicable standards for criteria pollutants. Comments must be received on or before September 11, 2015.
