The next phase

Meeting Phase 2 fuel efficiency and GHG emissions for heavy trucks will require multiple technology pathways-some of which are still on the horizon.

Called the “technology-advancing” phase of greenhouse gas (GHG) emissions and fuel efficiency standards, Phase 2 for 2021-2027 medium- and heavy-duty on-highway vehicles and engines is the encore to a generally considered successful Phase 1. While the first phase was largely dependent on off-the-shelf solutions, emerging technologies not in widespread use-or perhaps not even developed yet-are absolutely critical to satisfying the stricter targets in Phase 2.

The U.S. EPA's Christopher Grundler is quick to note that the standard is “technology neutral.”