The US Environmental Protection Agency (EPA) issued its final rule, “Greenhouse Gas Emissions Standards for Heavy-Duty Vehicles – Phase 3,” that sets stronger standards to reduce greenhouse gas emissions from heavy-duty (HD) vehicles beginning in model year (MY) 2027.

The new standards will be applicable to HD vocational vehicles (such as delivery trucks, refuse haulers, public utility trucks, transit, shuttle, school buses, etc.) and tractors (such as day cabs and sleeper cabs on tractor-trailer trucks).

The final Phase 3 standards build on EPA’s Heavy-Duty Phase 2 program from 2016 and maintain that program’s flexible structure, which is designed to reflect the diverse nature of the heavy-duty vehicle industry. The standards are technology-neutral and performance-based, allowing each manufacturer to choose what set of emissions control technologies is best suited for them and the needs of their customers.

Available technologies include advanced internal combustion engine vehicles, hybrid vehicles, plug-in hybrid electric vehicles, battery electric vehicles, and hydrogen fuel cell vehicles.

Relative to the earlier proposal, EPA’s final rule provides more time in the early model years of the program for the development of vehicle technologies and deployment of charging and refueling infrastructure. The final rule also includes flexibilities that will assist manufacturers in meeting the standards in the early years of the program while preserving incentives for early adoption of advanced technologies.

For heavy-duty vocational vehicles such as delivery trucks, refuse haulers, and public utility trucks, the Phase 3 standards vary according to vehicle type and range up to 60% stronger than the previous Phase 2 standards for MY 2032. For tractors such as day cabs and sleeper cabs on tractor-trailer trucks, the Phase 3 standards vary according to vehicle type and range up to 40% stronger than the previous Phase 2 standards for MY 2032.