Vehicle Fuel Economy and Greenhouse Gas Standards: Frequently Asked Questions [Updated June 1, 2021] [open pdf - 2MB]
From the Summary: "On January 20, 2021, President Joe Biden issued Executive Order 13990, 'Protecting Public Health and the Environment and Restoring Science to Tackle the Climate Crisis,' which directs federal agencies to review regulations and other agency actions from the Trump Administration, including the rules that revised the Obama Administration's vehicle fuel economy and greenhouse gas (GHG) emissions standards. Currently, the federal standards that regulate fuel economy and GHG emissions from new passenger cars and light trucks include the Corporate Average Fuel Economy (CAFE) standards promulgated by the U.S. Department of Transportation's National Highway Traffic Safety Administration (NHTSA) and the Light-Duty Vehicle GHG emissions standards promulgated by the U.S. Environmental Protection Agency (EPA). They are known collectively as the National Program. [...] Debate continues over the stringency, design, and purpose of the CAFE and vehicle GHG emissions standards. The debate is informed by analyses regarding (1) whether the Obama-era standards are technically and economically feasible; (2) the impact of the standards on GHG emissions targets and energy conservation; (3) whether the standards adequately address consumer choice, safety, and other vehicle policies, both domestic and international; and (4) whether the EPA and NHTSA reopening and rule revision actions were lawful."
CRS Report for Congress, R45204
Congressional Research Service: https://crsreports.congress.gov/