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Regulations for Emissions from Vehicles and Engines

Regulations for Greenhouse Gas Emissions from Commercial Trucks & Buses

On this page:

News and Events

Improvements for Heavy-Duty Engine and Vehicle Test Procedures, and other Technical Amendments

Final Rule Improvements Heavy Duty Engine and Vehicle Test

Heavy-duty (HD) Greenhouse Gas (GHG) Trailer Implementation Workshop

On November 16, 2016, EPA and NHTSA conducted a workshop on the certification process for trailers to comply with Phase 2 Greenhouse Gas Emissions and Fuel Efficiency Standards. For outreach materials related to the workshop, visit our Heavy-duty Greenhouse Gas (GHG) Trailer Implementation Workshop page.


EPA and the National Highway Traffic Safety Administration (NHTSA) are taking coordinated steps to enable the production of a new generation of clean vehicles, through reduced greenhouse gas (GHG) emissions and improved fuel use from onroad vehicles and engines.

In August 2011, in response to a Presidential Memorandum issued in May 2010. EPA in coordination with NHSTA issued greenhouse gas emissions and fuel economy standards for medium and heavy duty trucks manufactured in model years 2014-2018. The agencies estimate that the combined standards will reduce CO2 emissions by about 270 million metric tons and save about 530 million barrels of oil over the life of vehicles built for the 2014 to 2018 model years, providing $49 billion in net program benefits. The reduced fuel use alone will enable $50 billion in fuel savings to accrue to vehicle owners, or $42 billion in net savings.

Building on the success of the Phase I standards, in August 2016, EPA and NHTSA jointly finalized Phase 2 standards for medium- and heavy-duty vehicles through model year 2027 that will improve fuel efficiency and cut carbon pollution to reduce the impacts of climate change, while bolstering energy security and spurring manufacturing innovation.

The final phase two program promotes a new generation of cleaner, more fuel efficient trucks by encouraging the development and deployment of new and advanced cost-effective technologies. The product of four years of extensive testing and research, the vehicle and engine performance standards would cover model years 2018-2027 for certain trailers and model years 2021-2027 for semi-trucks, large pickup trucks, vans, and all types and sizes of buses and work trucks. The final standards are expected to:

  • Lower CO2 emissions by approximately 1.1 billion metric tons;
  • Save vehicle owners fuel costs of about $170 billion; and
  • Reduce oil consumption by up to two billion barrels over the lifetime of the vehicles sold under the program.
For more information, see:

List of Related Regulations

Below is a list of all regulations related to GHG emissions from commercial trucks and buses. 

Click the regulation titles for additional information, including:
  • Rule summaries;
  • Regulatory impact analyses;
  • Comment summaries;
  • Rule histories; and 
  • Fact sheets.*

*Note: Rule-related materials vary by rule.

Regulation Title Regulation Date
Repeal of Emission Requirements for Glider Vehicles, Glider Engines, and Glider Kits 2017/11
Final Rule for Phase 2 Greenhouse Gas Emissions Standards and Fuel Efficiency Standards for Medium- and Heavy-Duty Engines and Vehicles 2016/10
Direct Final Rule and Nonroad Technical Amendments for Heavy-Duty Engine and Vehicle 2013/06
Final Rule for Phase 1 Greenhouse Gas Emissions Standards and Fuel Efficiency Standards for Medium- and Heavy-Duty Engines and Vehicles 2011/09

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