Originally published in Bloomberg BNA's Daily Environment Report, 209 DEN B-1, 10/28/16.

On Oct. 25, the Environmental Protection Agency and the National Highway Traffic Safety Administration published more stringent greenhouse gas emissions standards and fuel efficiency requirements for medium- and heavy-duty engines and vehicles. These ‘‘Phase 2’’ standards apply to combination tractors, trailers pulled by combination tractors, heavy-duty pickup trucks and vans, and vocational vehicles such as buses, garbage trucks and concrete mixers, as well as engines that power combination tractors and vocational vehicles. The rules cover model years 2021 through 2027.