“The Clean Air Act gives EPA general authority to establish emissions limits for new motor vehicles for air pollutants that are found to pose a danger to humans. However, there is no reason to believe Congress ever contemplated that EPA’s authority to address automotive air pollution might be used to displace or supersede NHTSA’s fuel economy mandate under EPCA.”
Citation: Project 2025, Section 3.10: Department of Transportation, Diana Furchtgott-Roth, pages 658 and 659
Context:
This is an argument that fuel efficiency should trump emissions standards – in other words, if controlling emissions interferes with fuel economy, it should be ignored. You can have both, by the way.
“Since model year 2004, carbon dioxide (CO2) emissions have decreased by 24 percent as fuel economy has increased by 32 percent.” [Source]
Full contextual analysis of Section 3.10: Department of Transportation here.