In late September 2026 local time, the United States Department of Transport, together with the National Road Traffic Safety Authority (NHTSA), officially issued 2027 to 2032 final fuel economy rules for light passenger vehicles and trucks, which significantly revised the oil consumption reduction targets set during the Biden Government, and the new regulations are expected to come into effect by mid-November 2026, becoming one of the core landings for the renewable energy deregulated policy for the second term. Officially, this will significantly reduce the price of new cars and reduce the pressure on ordinary households to buy cars, but environmental organizations, some state governments and industry have stated that the new regulations will push up long-term vehicle costs and significantly increase carbon emissions, contrary to previous United States emissions reduction commitments.
On the first day of his second term of office, Trump signed an Executive Order to Unleashing US Energy, requiring all federal agencies to reassess mandatory rules relating to energy consumption, abolishing the target set by the Biden Government of “an average fuel economy of 55 miles/gallon in 2030 (approximately 4.3 litres/100 km) and an increase to 65 miles/gallon (approximately 4.6 litres/100 km) in 2032”, while abolishing the mandatory requirement of “50 per cent of new car sales by 2030”, officially stating that the target was “exceeding administrative intervention” and restricting the autonomy of the industry in production. In the second quarter of 2025, the United States Department of Transport issued an initial revised draft, proposing a downward adjustment of the 2032 fuel economy standard to 40 miles/gallon (approximately 5.9 litres/100 kilometres), while adjusting the classification rules for light trucks to include SUVs and pickups weighing more than 2.5 tons with a certain cargo capacity in the light truck category and applying more liberal fuel consumption requirements. After four months of public deliberations and large-scale lobbying in the automobile industry, the final rules were finalized in September 2026, further easing the requirements over the draft: The average fuel economy threshold for the 2027 car types is only 36 miles/gallon (approximately 6.5 litres/100 kilometres) and, thereafter, only 0.5 miles/gallon (approximately 0.09 litres/100 kilometres) per year will be required to reach the target by 2032, well below the rate of 3 miles/gallon (approximately 0.8 litres/100 kilometres) per year during the Biden administration. The Minister of Transport, Sean Duffy, stated at the Rules Conference that the previous fuel standards, which were “extreme environmental policies that abducted the products of the automobile industry”, had led to an increase in the average price of new cars due to compliance costs of over $12,000, which would be difficult for ordinary families to afford. The new rules would return options to consumers, and official estimates indicated that the average price of new cars sold under the new regulations between 2027 and 2032 would be between $3,000 and $5,000 lower than the average price of new cars sold under the old standards.
The impact of the rule adjustment covers a wide range of groups, with significant variations in the degree of benefit and risk of damage among different groups. The first category consists of ordinary car buyers and current owners: the officially measured car purchase discounts are mainly targeted at groups that purchase conventional fuel vehicles, but the environmental organization Natural Resources Protection Committee's independent calculations indicate that, as a result of an average increase of 15 per cent in fresh-off fuel consumption, the owner's average annual fuel expenditure would increase by approximately $500, and the additional cost of fuel for a vehicle would amount to $5,000 to $8,000 over a 10-year life cycle, offset by higher actual expenditure on car purchases, particularly for the commuter population, which travels over 15,000 kilometres per year. The second category is automobile manufacturers. The new regulations have significantly reduced the pressure on companies to comply and do not require significant investment in the development of hybrid, electric technologies to meet stringent fuel consumption requirements. Mainstream companies are expected to save over $8 billion per year in compliance costs, and some have announced adjustments to their 2027-type production plans to increase the share of conventional fuel vehicles. However, new-energy-type companies will face greater competitive pressures, and the cost advantages of conventional fuel vehicles may crowd out new-energy-type market space. The third category concerns environmental stakeholders and state governments. Official data indicate that the new regulations will result in cumulative additional emissions of about 2.8 billion tons of CO2 from light vehicles in the United States between 2027 and 2032, equivalent to 150 additional kWt of coal-fired power plants per year, and will make it difficult to achieve the goal of a 50 to 60 per cent reduction in United States carbon emissions by 2030 compared to 2005. Seventeen states, such as California, that have joined the Regional Emissions Alliance, have made it clear that a conflict between the new regulations and more stringent emission standards in the state will lead to two systems of compliance and increase unnecessary operating costs for state-owned vehicles.
After the new regulations were issued, multiple objections arose. EPA has filed a complaint with the Federal Court alleging that the Ministry of Transport did not adequately assess the public health impact of carbon emissions during the rule-making process, in violation of the requirements of the Clean Air Act, and requested the Court to rescind the new regulations. Seventeen states, such as California, have also jointly initiated lawsuits claiming that the federal Government does not have the power to overturn the emission standards set by the state government in accordance with the law and to require courts to issue a ban to prevent the new regulations from coming into force. Some motorists have also argued that, while short-term compliance costs have been reduced, in the long run they could undermine the global competitiveness of United States motor companies in the new energy sector — with more stringent fuel and carbon emission standards currently set in major markets, such as the European Union and China, which are expected to lose over $200 billion in exports if they are unable to meet compliance requirements in overseas markets. In addition, some Democrat MPs have proposed a bill that seeks to overturn the rules of the Ministry of Transport, but given the current Republican control of both Houses of Congress, it is extremely unlikely that it will be passed.
The first is the entry into force of the new regulations, which will take effect 60 days after the official publication of the Federal Gazette, with a projected landing time of mid-November 2026, with 2027 models first applying the new standards. This is followed by the adjustment of motor vehicles, which are expected to publish 2027 car types of production plans within the next six months, and some of which may clear up stock of cars that meet the old standards before the standards come into effect, giving them some discounts for purchasing vehicles. Thirdly, there has been legal progress, and the proceedings are expected to enter into the first instance stage in December 2026, and the new regulations may be delayed if the court issues an interim injunction. For consumers who plan to purchase cars by 2027, attention can be paid to the dynamics of stock-cleaning in automobiles, and decisions can be made over the long-term cost of vehicles of different types; for motorists, attention needs to be paid to the direction of their production and to the preparation of their careers ahead of time.