The U.S. Environmental Protection Agency (EPA) has decided to maintain its existing limits on emissions of greenhouse gases for light-duty vehicles through 2025.
Enacted by the Obama Administration in 2012, the emission standards coordinate with NHTSA Corporate Average Fuel Economy (CAFE) standards for a fleet average of 54.5 mpg (equivalent to about 38 mpg on window stickers) that same year.
The decision follows the July release of a Technical Assessment Report (TAR) by the EPA, National Highway Traffic Safety Administration (NHTSA), and California Air Resources Board (CARB) on automakers' ability to meet standards for 2022 through 2025.
That report noted that automakers have the technical ability to meet these standards, although unexpectedly high SUV sales might cause them to miss the mark slightly.
This was seized upon by industry lobbyists calling for more lenient standards as the NHTSA embarks on its own rulemaking following a so-called midterm evaluation of CAFE.
But in its voluminous "Proposed Determination" on the matter, the EPA said the standards for 2022-2025 should remain in place, largely reiterating points made in the July TAR.
EDITOR'S NOTE: An earlier version of this report did not make it clear that the EPA sets emission limits, while the NHTSA oversees fuel-economy standards. Starting with emission limits for 2012 vehicles, the two agencies have coordinated their standards, but the EPA does not directly set policy for fuel economy. The EPA decision Wednesday was widely (but incorrectly) reported to be about CAFE. We apologize for the error.
The rules are subject to review until April 2018, but EPA Administrator Gina McCarthy is pushing for final approval after taking comments through December 30.
This may be a move to finalize the decision before president-elect Donald Trump takes office.
The July TAR found that automakers were capable of meeting the 2025 goal and that it could be met by relying primarily on improvements in the efficiency of internal-combustion powertrains.
Transmissions with higher numbers of gears, downsized turbocharged engines with direct injection, lighter body structures, and improvements in aerodynamics could make that possible, the report said.
That would mean large numbers of hybrids, plug-in hybrids, and battery-electric cars wouldn't be necessary, something many automakers would likely appreciate.
Predictably, the EPA's decision to maintain current emission standards was praised by environmental groups.
2017 Toyota Prius Prime
"Loosening standards would cost consumers more, increase our dependence on oil, and put Americans at greater risk from a changing climate," said Luke Tonachel of the Natural Resources Defense Council.
The Sierra Club called the EPA decision "the first stop on the road map to clean transportation."
Consumers Union praised report, estimating that CAFE standards corresponding to the EPA rules could save consumers an average $4,800 over the life of a vehicle, even if gas prices remain at current low levels.
"The EPA's proposal to maintain robust fuel-economy standards is a big win for consumers," Shannon Baker-Branstetter, energy policy counsel for Consumers Union, said.
The industry response was less enthusiastic.
The Alliance of Automobile Manufacturers criticized what it calls an "extraordinary and premature rush to judgment" on the feasibility of the standards.
2016 Chevrolet Camaro’s exhaust tips
"The evidence is abundantly clear that with low gas prices, consumers are not choosing the cars necessary to comply with increasingly unrealistic standards," the group said.
The National Automobile Dealers Association also issued a statement saying that the existing fuel-economy standards would "halt progress on fuel economy," apparently by making new vehicles so expensive that no American will be able to buy them.
NADA said it "looks forward to working with the Trump Administration" to reverse or delay the fuel-economy rules.