On March 20, 2024, EPA released a final tailpipe emissions rule that sets new, more stringent emissions standards for greenhouse gas (GHG) and criteria pollutants for light-duty and medium-duty vehicles for model years (MY) 2027 through 2032. The transportation sector is the largest source of US GHG emissions and a contributor to ozone, particulate matter, and air toxics that have harmful health effects. EPA states that the standards will reduce over 7 billion tons of GHG emissions along with significant amounts of other criteria pollutants and air toxics, resulting in “substantial improvements in public health.”
The final rule incorporates comments on the proposed rule, new information, and issues raised in ongoing litigation about EPA’s previous vehicle emissions standards to produce standards grounded in EPA’s longstanding regulatory framework that reflect technological advances underway in the automotive industry. As we described in our summary of the proposed rule, EPA offered a proposed standard and three alternatives. The final rule follows the third alternative in the proposal, which has a slower ramp of stringency, especially in the early years, but results in a similar level of pollution reduction over time.
Read or download our analysis of the final EPA tailpipe emissions rule.