U.S. vehicle fleet fuel efficiency fell in 2019 to 24.9 mpg, EPA says U.S. vehicle fleet fuel efficiency fell in 2019 to 24.9 mpg, EPA says January 6, 2021 dzadmin Comments 0 Comment The EPA said fuel economy for the U.S. fleet fell by 0.2 mpg and most manufacturers are using banked credits to meet current compliance requirements.