DOT Lowers CAFE Target to 34.9 MPG and Closes Credit Trading in 2028

On September 28, 2026, the National Highway Traffic Safety Administration delivered its final rule for corporate average fuel economy through model year 2031. The measure, published as the Safer Affordable Fuel-Efficient Vehicles Rule III under the Department of Transportation’s “Freedom Means Affordable Cars” initiative, lowers the light-duty fleet target to 34.9 miles per gallon. Under previous standards, automakers faced a projected mandate of 50.4 mpg over that same timeline. With the 2024 industry average hovering near 30.1 mpg, the new requirement sets annual fleet efficiency increases between 0.5 and 1 percent through the remainder of the decade. Transportation Secretary Sean P. Duffy framed the decision in Washington as an intervention to reduce vehicle purchase costs by an estimated $1,300 per car.

The 892-page regulatory package alters the underlying math of automotive manufacturing by addressing two mechanisms at once. The first is the fleetwide target itself, which flattens penalty exposure for building large, gasoline-powered sport utilities and pickup trucks. The second is an administrative change that fundamentally disrupts industry balance sheets. Beginning in model year 2028, NHTSA will eliminate inter-manufacturer credit trading entirely. Under the text signed by NHTSA Administrator Jonathan Morrison, credit transfers between separate carmakers will close permanently after the 2027 model year.

For pure electric vehicle manufacturers, regulatory credit trading has operated as a steady revenue stream on quarterly balance sheets.

Financial filings show that Tesla accumulated more than $9 billion from selling regulatory credits over the past decade. Rivian and other electric entrants similarly used credit transfers to cushion capital expenditures during early manufacturing scale-ups. In hindsight, that revenue stream was already shrinking as traditional automakers expanded their own electrified offerings and built compliance buffers. Tesla reported credit revenues dipping toward $146 million in recent quarters, down noticeably from historical peaks. Under the finalized rule, credits banked through model year 2027 will retain a five-year trading shelf life, but newly generated credits earned in 2028 and beyond can only be used internally across an automaker’s own fleet. Rivian and other specialized electric manufacturers had counted on ongoing open-market credit monetization to offset facility investments in Illinois and Georgia.

For legacy automakers in Detroit and abroad, the lowered target alters how capital flows toward factory retooling. General Motors, Ford, and Stellantis had faced penalties or the continuing expense of purchasing external credits to bridge heavy truck production. Under the revised 34.9 mpg curve, boardrooms can redirect capital spending away from immediate, low-margin battery electric rollouts and toward long-life internal combustion updates and hybrid variations. The Alliance for Automotive Innovation, a trade association representing major carmakers in Washington, supported the recalibration as a necessary adjustment to retail market conditions. John Bozzella, the group’s chief executive, noted in a public release that aligning rules with showroom sales provides breathing room for domestic assembly plants.

Powertrain planners are now directing development capital back toward hybrid architectures and updated combustion designs. Hybrids offer a predictable path to meet the new 34.9 mpg fleet average without incurring the battery pack costs of 100-kilowatt-hour trucks. Ford had already expanded hybrid options on the F-150 and Maverick, while Toyota built its North American market share by keeping hybrid variants across its utility line. However, the regulatory easing does not leave combustion platforms entirely unchanged. Model year 2030 introduces a revised classification system that reassigns many car-based crossovers out of the light-truck category and into passenger cars.

That classification revision will reclassify roughly half of today’s crossover sales as passenger automobiles. The Fast Lane Truck, a Colorado-based automotive publication, reported that moving car-like crossovers into the passenger category prevents manufacturers from shielding thirsty truck lines behind high-riding compact unibodies. The resulting fleet calculations mean that light trucks will require their own dedicated efficiency improvements, including stop-start revisions, cylinder deactivation, and eight- or ten-speed automatic transmissions. Agency projections show the truck fleet requirement settling near 26.4 mpg by 2031 once smaller crossovers are categorized separately.

Outside the engineering centers, pump prices present a different economic calculation for motorists. At the time of NHTSA’s announcement, regular unleaded gasoline averaged $4.48 per gallon nationally, with diesel sitting at $6.53 per gallon amid Middle Eastern disruptions. The Natural Resources Defense Council, an environmental advocacy organization based in New York, pointed out that the relaxed rules will cause vehicles to burn roughly 100 billion additional gallons of fuel through 2050. NHTSA’s own documentation acknowledged higher lifetime operating expenses for drivers, estimating roughly $1,400 in additional fuel expenses over the lifespan of a vehicle. The Department of Transportation maintained that the $1,300 upfront retail savings and increased manufacturing flexibility balance those lifetime fuel figures.

State-level legal challenges from California and environmental groups are expected before the sixty-day implementation window expires. Section 177 states, which follow California’s clean car standards, face an increasingly fractured regulatory landscape if federal and state requirements diverge further. Automotive suppliers in Michigan, Ohio, and Indiana are balancing component tooling for engines that now have extended production timelines, alongside battery facilities that have already broken ground. Federal docket records indicate multiple state attorneys general have already begun filing notices of appearance to contest the final rule in the federal appellate courts.