The US Department of Transportation has finalised a plan to weaken fuel economy standards, undoing a key Biden-era requirement. The change allows new vehicles to use more fuel, which the Trump administration says will reduce their purchase price; critics warn it will raise fuel bills and worsen pollution-related costs.

The Biden rules aimed for a fleet average of 50.4 miles per gallon by model year 2031, while the new target is 34.9 mpg, only modestly above the previous 2024 target of 30.1 mpg. The administration estimates the change will cut the average new-car price by $1,300 and save $138 billion over five years, figures that have been disputed. The former standards were projected to save $23 billion in fuel costs and more than $600 in petrol over a vehicle’s lifetime.