Editing Fuel efficiency (section)

==Fleet efficiency==
[[File:1975- US vehicle production share, by vehicle type.svg |thumb |Trucks' share of US vehicles produced, has tripled since 1975. Though vehicle fuel efficiency has increased within each category, the overall trend toward less efficient types of vehicles has offset some of the benefits of greater fuel economy and reduction in carbon dioxide emissions.<ref name=EPA_AutomotiveTrends_202212>{{cite web |title=Highlights of the Automotive Trends Report |url=https://www.epa.gov/automotive-trends/highlights-automotive-trends-report |website=EPA.gov |publisher=U.S. Environmental Protection Agency (EPA) |archive-url=https://web.archive.org/web/20230902145941/https://www.epa.gov/automotive-trends/highlights-automotive-trends-report |archive-date=2 September 2023 |date=12 December 2022 |url-status=live}}</ref> Without the shift towards SUVs, energy use per unit distance could have fallen 30% more than it did from 2010 to 2022.<ref name=GlobalFuelEfficInit_202311>{{cite web |last1=Cazzola |first1=Pierpaolo |last2=Paoli |first2=Leonardo |last3=Teter |first3=Jacob |title=Trends in the Global Vehicle Fleet 2023 / Managing the SUV Shift and the EV Transition |url=https://www.globalfueleconomy.org/media/792523/gfei-trends-in-the-global-vehicle-fleet-2023-spreads.pdf |publisher=Global Fuel Economy Initiative (GFEI) |archive-url=https://web.archive.org/web/20231126092826/https://www.globalfueleconomy.org/media/792523/gfei-trends-in-the-global-vehicle-fleet-2023-spreads.pdf |archive-date=26 November 2023 |page=3 |doi=10.7922/G2HM56SV |date=November 2023 |url-status=live }}</ref>]]
Fleet efficiency describes the average efficiency of a population of vehicles.  Technological advances in efficiency may be offset by a change in buying habits with a propensity to heavier vehicles that are less fuel-efficient.<ref name=EPA_AutomotiveTrends_202212/>