Core Viewpoint - The Biden administration's fuel-efficiency standards for carmakers require achieving approximately 50 miles per gallon by 2031, while the Trump administration's proposal aims to reduce this requirement to 34.5 miles per gallon [1] Group 1 - The Biden-era rules set a target of 50 miles per gallon for fuel efficiency by 2031 [1] - The Trump administration's proposal would significantly lower the fuel-efficiency requirement to 34.5 miles per gallon [1]