The U.S. Environmental Protection Agency proposed a delay in phase-in for emission standards set in 2024, and the Alliance for Automotive Innovation announced its support for the new timeline. 

If enacted, the EPA’s proposal would delay Tier 4 criteria emission standards for light-and medium-duty vehicles for two years, taking effect with model year 2029 instead of model year 2027. The end goal of full implementation by model year 2032 would remain in place. 

Alliance for Automotive Innovation President and CEO John Bozzella called the delay "a smart and necessary step ... that makes a lot of sense given current market conditions.”  The trade group represents automakers that do business in the U.S.

Tier 4 was set in April 2024 during the Biden administration as the Multi-Pollutant Emissions Standards for MYs 2027 and Later Light-Duty and Medium-Duty Vehicles rule. 

According to the EPA, the proposed amendment is “in response to the overwhelming rejection of [electric vehicles] by the American people and manufacturers shifting away from them.”

Many automakers have rolled back their EV investments, including General Motors, Ford and Stellantis, as consumer demand in the states dropped after the loss of federal EV incentives last year. However, recent data showed electrified-vehicle sales are holding steady and even increasing in the case of hybrids as gas prices surge due to the ongoing war in the Middle East.