The average production-weighted carbon dioxide (CO2) emissions for new model year (MY) 2021 light-duty vehicles was 348 grams per mile, down from 681 grams per mile for new vehicles in MY 1975 ‒ a decrease of 49%. From the mid-1970s to the mid-1980s, there was a rapid decline in average CO2 emissions as manufacturers produced more vehicles with smaller displacement engines. From the mid-1980s to 2004, average CO2 emissions of new light-duty vehicles gradually rose as consumer demand favored light trucks over cars and vehicle performance increased. Although consumer demand for light trucks and higher performance continued unabated from MY 2005 to 2021, advanced technologies improved vehicle efficiency and reduced the average CO2 emissions of new light-duty vehicles by about 22% in that timeframe.
Note: Data for 2021 are preliminary.
Source: U.S. Environmental Protection Agency, 2021 EPA Automotive Trends Report, EPA-420-R-21-023, November 2021.