The Department of Transportation announced new fuel-economy rules today as the Trump administration rolls back stringent requirements passed during the Biden presidency. The new standards will require a fleet-average fuel economy of 34.9 mpg by model year 2031, down from 50.4 mpg under the Biden-era rules.The new rules also aim to make it more difficult for automakers to use design and equipment to classify small SUVs as light trucks and eliminate the CAFE credit trading program.