Since the passage of the Clean Air Act in 1970, the Environmental Protection Agency has worked collaboratively with the automobile industry to reduce air pollution from light-duty vehicles. This year marks the 50th anniversary of the EPA’s Automotive Trends Report, an annual publication that explains the agency’s complex regulatory framework and documents the compliance of individual automakers. The authoritative report presents a comprehensive data set on every light-duty vehicle sold in the United States since 1975 and provides sophisticated analysis of key trends shaping the industry’s environmental outcomes.
The 2024 report includes finalized data from the 2023 model year and is preceded by a letter from EPA Administrator Michael Regan recognizing the 50-year milestone. The congratulatory statement honors the agency’s career professionals, highlighting accomplishments that “ultimately led to an impressive 99 percent reduction in common vehicle tailpipe pollutants, such as hydrocarbons, carbon monoxide carbon, nitrogen oxides and particles. The letter goes on to highlight the scientific value of the data set as the auto industry struggles to mitigate carbon dioxide from tailpipes, an inevitable byproduct of gasoline combustion and a substantial contributor to climate change.
Carbon dioxide emissions are now the focus of the report, and the latest statistics provide encouraging news. The average 2023 model year light-duty vehicle produced 319 grams of carbon dioxide per mile (g/mi), an improvement of 18 g/mi compared to the 2022 model year. The respectable reduction in tailpipe emissions corresponded to a year-over-year fuel economy gain. of 1.1 MPG, with the average 2023 vehicle getting 27.1 miles per gallon.
The fifty year history of real fuel economy trends can be divided into three distinct periods. Between 1975 and 1987, fuel economy rapidly improved as the United States responded to the Arab oil embargo, increasing from 13.1 MPG to 22.0 MPG. As concerns about energy independence faded in the late 1980s, gasoline consumption began to slowly decline, dropping steadily to a low of 19.3 MPG in 2004. A strong upward trend emerged in 2005, as growing apprehension about climate change catalyzed a relentless effort to mitigate carbon emissions from exhaust fumes. dioxide. The 2023 figures for MPG and CO2 emissions are the latest in a series of historic records that began in 2009.
The EPA attributes most of the recent progress to increased production of battery electric vehicles and plug-in hybrid electric vehicles. When BEVs and PHEVs are statistically removed from the 2023 model year fleet, average CO2 emissions increase to 357 g/mi and average fuel economy drops to 24.9 MPG. These hypothetical averages are identical to the finalized results for the 2017 model year. Automotive technologies that increase the fuel economy of conventional internal combustion vehicles are being undermined by consumers’ tendency to favor larger, more powerful models, and it will be difficult to further improve their effectiveness.
The 50th anniversary of the Automotive Trends Report coincides with the start of an era of environmental innovation. Maintaining progress in the fight against carbon dioxide will now depend on the increased proliferation of our cleanest powertrains, and there is good reason for hope as we reflect on the promising results of 2023.
