The final version of the rule, officially dubbed Phase 2 of the Greenhouse Gas Emissions Standards and Fuel Efficiency Standards for Medium- and Heavy-Duty Engines and Vehicles, was sent to the White House this week for review.
The National Highway Traffic Safety Administration and the Environmental Protection Agency introduced the proposed rule last June. The standards will begin taking effect for trailers for model year 2018 units and 2021 for tractors. The plan goes through 2027, when the entire vehicle – engine, truck and trailer – will be required to meet certain standards.
When the proposed rule was announced, the EPA said the standards would “significantly reduce carbon emissions and improve fuel efficiency of heavy-duty vehicles, helping to address the challenges of global climate change and energy security.”
A month later, in July, the full text of the proposed rule was released when the 629-page Notice of Proposed Rulemaking was published in the Federal Register.
The trailer standards, which will begin to be implemented first, proposed aerodynamic and tire improvements to help reduce fuel consumption of the entire tractor-trailer by 3-to-8 percent from the model year 2017 baseline. Examples of improvements that can be made to trailers by manufacturers include low rolling resistance tires, automatic tire inflation systems, weight reduction, side and rear fairings, gap closing devices and undercarriage treatment for box trailers.
The tractor standards proposed for model year 2027 would lower carbon dioxide emissions and fuel consumption by up to 24 percent from a 2017 model Phase 1 tractor. The proposed rule said these standards could be met by improvements in the waste heat recovery systems for engines, transmission, driveline, aerodynamic design, tire rolling resistance, idle performance and other accessories of the tractor.
The agencies also proposed a 4.2 percent reduction in carbon dioxide emissions and fuel consumption from 2017 baseline engines. The engine standard requirements will begin in 2021 and become stricter in 2024 before meeting the 4.2 percent goal in 2027.
A number of trucking industry stakeholders commented on the proposed rule last summer, agreeing generally with the reasoning behind the rulemaking, but disagreeing with the rule itself. Most concerns about the rule dealt with the cost that would be incurred by equipment purchasers once the new standards are in place.
The White House Office of Management and Budget generally has 90 days to clear the rulemaking for publication in the Federal Register, barring special circumstances.
