Weakened US fuel-efficiency rules and promises of cheaper cars could see drivers pay higher running costs while also increasing carbon emissions.

The United States Department of Transportation has weakened fuel efficiency rules under the Freedom Means More Affordable Cars initiative. This move aims to lower vehicle prices, with the Trump administration claiming US taxpayers will save $138 billion over five years, as automakers will no longer need to invest in more fuel-efficient fleets.

However, this does not account for rising gas prices due to Middle East conflicts disrupting global supply. Fuel economy standards have previously saved hundreds of billions of dollars for drivers, according to Democratic Senator Sheldon Whitehouse. The new Corporate Average Fuel Economy (CAFE) rules would require vehicles to achieve an average fuel efficiency of 35 miles per gallon by 2031, down from 50 miles per gallon.

The US National Highway Traffic Safety Administration estimates the standards could have saved 70 billion gallons of fuel over 25 years. The Union of Concerned Scientists claims the earlier version of CAFE regulations saved US consumers $321 billion at the gas pump since 2010. Climate change advocates argue that diluting these fuel efficiency standards is a significant setback for near-term climate goals, as transportation accounts for nearly 28% of US greenhouse gas emissions.

The move could prevent over 710 million metric tons of carbon dioxide emissions by 2050. The trend is seen as a step backward, with experts warning it risks keeping inefficient combustion engines on the road longer and increasing overall oil usage and emissions.