Vehicle-related air pollution rules under review by the Trump administration
The U.S. Environmental Protection Agency is considering postponing the implementation of several Biden-era regulations aimed at significantly reducing vehicle-related air pollution. If confirmed, the decision would roll back measures that were central to the previous administration’s climate strategy and public health agenda.
According to the Trump administration, the delay would reduce regulatory pressure on automakers and consumers, effectively dismantling one of the most ambitious frameworks ever adopted in the United States to address climate change through transport policy.
Trump plans to delay vehicle pollution standards
This week, President Trump announced that the Department of Transportation would substantially ease fuel efficiency requirements for tens of millions of new passenger cars and light trucks. Administration estimates suggest the changes could save U.S. consumers nearly $109 billion over five years, lowering the average cost of a new vehicle by about $1,000.
Biden-era vehicle-related air pollution regulations
In 2024, the EPA finalized new rules establishing stricter limits on harmful emissions from light- and medium-duty vehicles. The regulations were designed to steer consumers toward cleaner cars while reducing smog-related air pollution and improving public health outcomes. The standards were set to be phased in gradually through 2032.
Transportation remains the largest source of greenhouse gas emissions in the United States. Under the Biden administration, tax credits were introduced to encourage the purchase of electric vehicles, alongside tougher efficiency standards for automakers to accelerate the shift toward less polluting models.
Rollback of vehicle-related air pollution protections
In March, EPA Administrator Lee Zeldin said the agency intended to reconsider the 2024 rules. Those standards would have cut tailpipe emissions from the entire passenger vehicle fleet by nearly 50% by 2032 compared with projected 2027 levels.
Under the Biden-era framework, emissions of key air pollutants such as nitrogen oxides were expected to fall by 50% for light-duty vehicles and by 58% for medium-duty vehicles by 2032. The EPA also projected that between 35% and 56% of new vehicles sold between 2030 and 2032 would be electric.
Lower fuel efficiency targets for cars and trucks
The Biden administration had required automakers to boost fuel efficiency for passenger cars and light trucks to nearly 50 miles per gallon by 2031, roughly equivalent to 21 kilometers per liter.
The plan outlined this week would instead lower the target to 34.5 miles per gallon by 2031. As part of the proposed delay, the EPA is now considering keeping the 2026 standard in place for an additional two years, giving the agency time to reassess the Biden-era rules.
The postponement would also allow regulators to review how these benchmarks are set, according to a U.S. government official cited by Reuters. The EPA is reportedly prepared to revoke the scientific finding that underpinned greenhouse gas emission standards for motor vehicles, a move that could have far-reaching implications for U.S. climate and transport policy.