Passenger Cars/Light-Duty Trucks
Current emissions standards for model years 2022-2025 are expected to achieve an industry-wide fleet average of 173 grams of carbon dioxide equivalent (CO2e) per mile in model year 2025, which is projected to be equivalent to 51.4 mpg if the automotive industry meets the target exclusively through fuel economy improvements. EPA also projects that automakers could meet this emissions compliance level with average real world/label fuel economy of 36 mpg.
In the final weeks of the Obama administration in January 2017, EPA determined that the emissions standards developed in 2012 for model years 2022-2025 remained appropriate. EPA cited the success of automakers in meeting early standard requirements and a seven-year growth in U.S. auto sales as reasons to expect that automakers could affordably continue to meet the standards. The California Air Resources Board concurred with the EPA’s determination in its own midterm review of California’s vehicle standards. California found that automakers were successfully and affordably deploying advanced technologies to meet fuel economy requirements and the state’s zero-emission vehicle program.
In March 2017 following a change in administrations, EPA under the Trump administration announced that it would revisit the midterm review decision to maintain emissions standards through 2025, took public comment, and held a public hearing.
In April 2018, EPA issued a reconsideration of the midterm evaluation of the light-duty vehicle emissions standards through 2025, concluded that the standards were based on outdated information and that more recent information suggested that the current standards may be too stringent, making vehicles less affordable. EPA concluded that since the 2012 rulemaking finalizing the standards, expectations about gas prices and consumer adoption of advanced technology vehicles had changed.
EPA’s formal rule-making would revise these standards. Meanwhile, a California-led group of 17 states and the District of Columbia sued in federal court to challenge EPA’s reconsideration. The group includes California, Connecticut, Delaware, the District of Columbia, Illinois, Iowa, Maine, Maryland, Massachusetts, Minnesota, New Jersey, New York, Oregon, Pennsylvania, Rhode Island, Vermont, Virginia, and Washington – states representing roughly 43 percent of the market for new car sales and 44 percent of the country’s population. The lawsuit alleges that EPA’s decision lacked scientific justification.
CARB is also considering amending its regulations so that only automakers that comply with the Obama administration GHG emissions standards will be “deemed to comply” with California standards, meaning that compliance with the new emissions standards set under the Trump administration may not equate to compliance with California standards.
A separate issue is that NHTSA can only develop fuel economy standards five model years at a time, so its 2017-2025 standards, announced in 2012, were only augural – or a prediction – for model years 2022-2025. In July 2017, NHTSA announced that it is conducting an environmental impact statement for model year 2022-2025 standards for passenger cars, light trucks, and medium-duty passenger vehicles.
History of Vehicle Standards
The 1975 Energy Policy and Conservation Act directed the U.S. Secretary of Transportation to establish Corporate Average Fuel Economy (CAFE) standards for new passenger cars. CAFE is the sales-weighted average fuel economy in miles per gallon (mpg) of the vehicles in a manufacturer’s fleet. This law was updated in 2007, when Congress increased the fuel economy standards for passenger vehicles and also established efficiency standards for medium- and heavy-duty vehicles.
California is the only state allowed to set its own air emissions standards for motor vehicles. California was granted an exception under the Clean Air Act because the state had already implemented standards in 1966 to address its critical smog problem and had established an Air Resources Board (CARB) to oversee them. The Clean Air Act states EPA shall grant a waiver if California’s standards are necessary to meet compelling circumstances and are at least as stringent as federal standards. Other states may choose to adopt California’s vehicle emissions standards without EPA approval. Fifteen states, making up 40 percent of the U.S. auto market, currently follow at least some of California’s vehicle emissions standards, including its fuel economy standards.
In April 2010, EPA and NHTSA finalized the first harmonized set of national program standards for Model Year 2012-2016 light-duty vehicles with the cooperation of major automakers and the state of California. These standards applied to passenger cars, light-duty trucks, and medium-duty passenger vehicles. The standards are based on the vehicle’s footprint, which is a measure of vehicle size. Footprints are divided into two categories: passenger vehicles and light trucks, the latter of which includes pickup trucks, vans, and sport utility vehicles. Under the National Program, EPA established GHG emissions standards and NHTSA established CAFE standards; both sets of standards were harmonized to produce one target for automakers to meet.