New proposed standards aimed at cutting emissions from heavy-duty vehicles as part of the Biden administration’s Clean Trucks Plan could also impact construction equipment.

The standards, released March 7 by the U.S. Environmental Protection Agency, would reduce nitrogen oxide (NOx) emissions from heavy-duty gasoline and diesel engines and would lower NOx emissions up to 60% by 2045. While primarily concerned with on-highway vehicles like trucks and buses, it also includes plans for other categories such as heavy-duty compression-ignition engines, which are used in nonroad machines, including construction equipment. Some of the most significant NOx reductions would be seen in vehicles that are moving at low speeds or idling, EPA says.

The proposal calls for longer useful life periods for engines, and EPA says it would push manufacturers to build more durable engines and install emission controls. EPA also wants longer emissions warranty periods to increase the number of useful life miles covered and make it less likely for owners to tamper with emissions controls. 

The stronger standards would take effect beginning with model year 2027 vehicles. The EPA has proposed either implementing the full set of new standards starting that year, or phasing in stronger standards for 2027 and then implementing the full standards in model year 2031.

EPA last revised its on-highway heavy-duty trucks NOx standards in 2001. The newly proposed standards would lean on recent technological advancements to drastically cut pollution associated with health problems, and help advance the transportation sector closer toward a zero-emissions future, said EPA Administrator Michael Regan in a statement.

Fleet Turnover

Truck and engine manufacturers’ groups said they would work with EPA on developing the new standards. In a statement, the Diesel Technology Forum said it would be important to ensure truckers are able to invest in the advanced products that emerge as a result of the standards, otherwise, there’s a risk that older vehicles with higher emissions and lacking particulate traps or selective catalytic reduction technology will remain in service longer. 

The Truck and Engine Manufacturers Association (EMA) wrote in a statement that new rules would need to facilitate fleet turnover to replace vehicles manufactured before the current standard takes effect. It added that EPA should help lead a strategy to achieve zero-emission vehicles by investing in electric charging stations, hydrogen fuel development and purchase incentives.

“It is imperative the new rule facilitate the transition to newer, cleaner trucks so we can achieve lower NOx emissions as soon as possible,” EMA President Jed Mandel said.

Environmental advocates say the EPA’s proposal aren’t strong enough. Peter Zalzal, senior counsel and associate vice president for clean air strategies at Environmental Defense Fund, called the proposal an important start, but said in a statement that the plans would not ensure the needed levels of zero-emission vehicle deployment.

The proposed standards are the first for EPA's Clean Trucks Plan. Introduced in August 2021, the plan aims to roll out additional pollution-reduction regulations for trucks and buses during the next three years.

EPA intends to finalize its proposed standards by the end of the year. The agency says it will announce a date for a public hearing.