In 2023, the U.S. achieved its highest vehicle fuel economy and lowest greenhouse gas emissions, with new vehicles averaging 27.1 mpg and CO2 emissions at a record low of 319 grams per mile. Despite progress, the EPA warns that further reductions are essential, as passenger cars and light trucks still contribute nearly 17% of total U.S. GHG emissions. The rise of electric and plug-in hybrid vehicles is pivotal, with their production increasing from 6.7% in 2022 to 11.5% in 2023, projected to reach 14.8% in 2024.