Efficiency technology potential for heavy-duty diesel vehicles in the United States through 2035
Policy update
U.S. EPA Phase 3 greenhouse gas emission standards for heavy-duty vehicles
In April 2024, the U.S. Environmental Protection Agency (EPA) introduced Phase 3 GHG emission standards for heavy-duty vehicles (HDVs), covering model years 2027 to 2032. These standards target substantial reductions in CO2 emissions from trucks and buses, aiming for up to a 60% emissions reduction for vocational trucks and 40% for tractor trucks by 2032. The new rules allow manufacturers flexibility in how they achieve these goals without mandating the sale of zero-emission vehicles (ZEVs).
Key policy elements include:
- Emission reduction targets: CO2 emissions must be reduced by up to 60% for vocational trucks and 40% for tractor trucks by model year 2032.
- ZEV adoption: ZEVs are expected to make up a larger portion of vehicle production, but there is no requirement to sell them.
- Credit transfer across vehicle averaging sets: new provisions for manufacturers to achieve compliance by pooling and trading emission credits across different weight-based averaging sets.
- Economic and environmental impact: The standards will cut 1 billion metric tons of CO2 emissions and generate $13 billion in annual benefits by 2055.
- Battery and hydrogen vehicle requirements: New rules include monitoring battery health and requiring warranties for key battery electric and hydrogen fuel-cell electric vehicle components.
- A 2026 assessment of charging and refueling infrastructure growth will be performed in collaboration with Department of Energy and Department of Transportation