On July 18, 2018, a divided panel of the U.S. Court of Appeals for the District of Columbia Circuit (D.C. Circuit) ordered a stay of a recent Environmental Protection Agency (EPA) action that would allow manufacturers to continue to produce trucks with engines that do not comply with the agency’s Clean Air Act caps. In so ruling, the D.C. Circuit expressly stated that the stay “should not be construed in any way as a ruling on the merits of that motion” and ordered the EPA to submit responsive briefs July 25.