"The Trump administration on Friday moved to relax fuel efficiency standards for medium- and heavy-duty commercial trucks.
The Transportation Department took aim at Obama-era standards, arguing that they exceed the scope of the government’s authority.
The Obama administration set standards for both the whole vehicle and its engine. The Trump administration now says that the government does not have the authority to set engine standards, it and published a new interpretation saying so.
While the new interpretation does not formally wipe out the Obama-era engine standards, the department implied in a press release that it would not enforce them while it finalizes a rule to formalize the change."
Source: The Hill, 08/31/2026
