The Environmental Protection Agency made good on its promise to issue a final rule on heavy-duty truck tailpipe emissions by the end of the year, but the first take on the rule from engine manufacturers and trucking organizations is that compliance will be difficult.
The agency earlier this year proposed two options for drastically reducing nitrous oxide (NOx) emissions: a two-step process with standards getting progressively tighter in model years (MY) 2027 and 2031, or a one-step standard in 2027 that would be less aggressive in cutting emissions.
EPA chose a one-step emission standard change in 2027, but one that is “largely consistent” with the original and more strict two-step option, according to the agency.
“The final new numeric NOx standards will result in the greatest degree of emission reduction achievable for a national program starting in MY 2027 through the application of technology that the [EPA] Administrator has determined will be available starting in MY 2027, after giving appropriate consideration to cost, energy, and safety factors associated with the application of such technology,” EPA stated.
The new standards — the first revision for NOx pollution in 20 years — will be more than 80% stronger, increase the useful life of governed vehicles by 1.5 to 2.5 times, and yield emissions warranties that are 2.8 to 4.5 times longer than current standards, according to EPA. The rule also includes provisions for longer engine useful life and warranty periods.
“The rule also requires manufacturers to better ensure that vehicle engines and emission control systems work properly on the road,” the agency noted. “For example, manufacturers must demonstrate that engines are designed to prevent vehicle drivers from tampering with emission controls by limiting tamper-prone access to electronic pollution controls.”
The Truck and Engine Manufacturers Association (EMA), which had preferred EPA’s proposed one-step 2027 standard option, contended that the final rule “is very stringent and will be challenging to implement,” stated EMA President Jed Mandel.
However, “our members are fully committed to working with the EPA and other stakeholders for its successful implementation,” Mandel said. “Ultimately, the success or failure of this rule hinges on the willingness and ability of trucking fleets to invest in purchasing the new technology to replace their older, higher-emitting vehicles.”
Chris Spear, American Trucking Associations president and CEO, is assessing the effect the rule will have on its members and agreed that EPA’s success in eliminating pollution through the rule hinges on the purchasing decisions made by the trucking industry.
“ATA remains extremely concerned over the potential growth of state patchworks of NOx emission standards that will create havoc for an industry that operates across local, state and international boundaries,” Spear added. “We hope EPA and the California Air Resources Board [CARB] will ultimately agree to a uniform, single standard that best achieves our nation’s environmental goals.”
CARB’s NOx rule, which became effective in December 2021, requires more stringent emission standards for heavy-duty engines beginning with 2024 model year engines, becoming more stringent with 2027 and subsequent model year engines.
Todd Spencer, Owner-Operator Independent Drivers Association president and CEO, had argued that both options as initially proposed by EPA were unworkable and ultimately unaffordable for drivers. Spencer said the final rule does not change that outlook for his members.
“If small business truckers can’t afford the new, compliant trucks, they’re going to stay with older, less efficient trucks or leave the industry entirely,” he said. “Once again, EPA has largely ignored the warnings and concerns raised by truckers in this latest rule.”
The rule goes into effect 60 days after it is published in the Federal Register.