Press release

Adoption of Phase 3 Greenhouse Gas rule for heavy-duty vehicles moves U.S. closer to climate goals

(Washington, DC) (March 29, 2024) — Today, the U.S. Environmental Protection Agency (EPA) adopted final Phase 3 greenhouse gas emission standards for heavy-duty vehicles, originally proposed in April 2023. The new standards move the United States closer to achieving domestic and international climate goals by requiring manufacturers to deploy more efficient vehicles beginning in model year (MY) 2027, including more efficient internal combustion engines and electric drive powertrains. The specifics of the rule can be found here.

The finalization of this rule comes at the tail end of a multi-year effort by the Biden Administration to accelerate the decarbonization of the bus and truck fleet following its adoption of the Bipartisan Infrastructure Law in 2021 and the Inflation Reduction Act in 2022.

The rule sets new requirements manufacturers will need to meet. They can do so with low-cost vehicle efficiency technologies, including more efficient engines, advanced transmissions, vehicle weight reductions, and improved vehicle aerodynamics. Manufacturers can also deploy an increasing number of zero-emission vehicles with more than 200 models already available today.

As a result of today’s action, the transition from large internal combustion engines (ICE) to electric vehicles (EV) is more certain. Americans can expect the future heavy-duty vehicle fleet will produce 1 billion fewer metric tons of CO2 between 2027 and 2055, resulting in over 22 billion dollars in annualized net benefits from premature deaths and other clean air and climate benefits, when combined with the 2023 NOx engine standard.

The EPA has issued a string of significant announcements that set the stage for cleaner trucks and buses in the U.S., including a 2023 heavy-duty engines and vehicles standard to control criteria pollutant emissions, clean school bus grants, a new clean ports program, and a shared ‘all-of-government’ national zero-emission freight corridor strategy, which will focus on deploying infrastructure along key freight hubs. Today’s action completes the EPA’s Clean Trucks Plan to reduce greenhouse gas emissions and other harmful air pollutants from heavy-duty trucks. And it complements the agency’s final multi-pollutant standards for light- and medium-duty vehicles covering model years 2027-2032.

“Heavy-duty vehicles literally do the heavy work that powers the U.S. economy,” says ICCT Acting Executive Director Rachel Muncrief. “We applaud EPA Administrator Regan and the agency staff for delivering a historic third phase of its greenhouse gas emission standards. This step is one of many steps still to come on the path to meet our freight decarbonization goals.’


Media Contact:
Kelli Pennington,

About the International Council on Clean Transportation
The International Council on Clean Transportation (ICCT) is an independent research organization providing first-rate, unbiased research and technical and scientific analysis to environmental regulators. Our mission is to improve the environmental performance and energy efficiency of road, marine, and air transportation, in order to benefit public health and mitigate climate change. Founded in 2001, we are a nonprofit organization working under grants and contracts from private foundations and public institutions.

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