Quick Facts:
- What changed: New CAFE standards target about 34.5 mpg fleetwide for 2031, down from 50.4 mpg, per the proposal.
- Timing: Trump approved the rule September 26, 2026; DOT set the release for Monday, September 28.
- Covers: Passenger cars and light trucks, including half-ton pickups and most SUVs.
- Not covered: Heavy-duty 2500 and 3500 pickups, which fall under a separate National Highway Traffic Safety Administration (NHTSA) program.
- Penalty for missing the target: $0 since the July 4, 2025, budget law.
- Real-world gap: NHTSA says real-world mileage runs 20% to 30% below the CAFE figure.
- Who feels it most: Truck and SUV shoppers weighing a 2026 or 2027 purchase.
 6 min read
In This Article
Overview
The new federal CAFE standards cut the fleetwide fuel economy target for model year 2031 to about 34.5 mpg. For comparison, the 2024 rule it replaces aimed for 50.4 mpg by the same year. President Trump said on Saturday, September 26, he approved the rule. Transportation Secretary Sean Duffy then set the formal release for Monday. For truck owners, though, the bigger change came last year, when Congress cut the fine to $0.
The 34.5 mpg figure comes from the December 2025 DOT proposal. Reports ahead of the release point to the same number. Under the proposal, light-truck targets rise 0.7% in 2027 and 0.25% a year from 2029 through 2031. By contrast, the 2024 rule planned 2% yearly gains for trucks from 2029.
Before you hold those numbers up to a window sticker, know the difference. CAFE math relies on an older two-cycle lab test. Real-world mileage therefore runs 20% to 30% below the CAFE figure, per the Alternative Fuels Data Center. A 34.5 mpg fleet average works out to roughly 24 to 28 mpg on the road.
Your own truck’s number is the one you pay for, and AAA put regular gas at $4.47 a gallon on Sunday. BlueDriver Bluetooth Pro, OBDLink MX+, and ANCEL BD310 log trip fuel economy and trouble codes on 1996-plus vehicles. Plug one in, and you see what your rig burns on the highway and on the trail.
Bluetooth OBD-II Scanners for Trip MPG
Bluetooth OBD-II Scan Tools for Trip Fuel Economy and Codes
Key Facts: Old vs. New CAFE Standards
| Item | 2024 Rule | New Rule |
|---|---|---|
| 2031 fleetwide target | 50.4 mpg (projected) | About 34.5 mpg (projected) |
| Model years | 2027 to 2031 | Resets 2022 to 2031 |
| Fine for missing the target | $0 since July 2025 | $0 |
| Credit trading between automakers | Allowed | Ends in model year 2028 (proposal) |
| Crossovers and small SUVs | Many counted as light trucks | Moved to passenger cars (proposal) |
| Heavy-duty 2500 and 3500 pickups | Separate program | Separate program, reset planned |
| DOT cost claim | Over $600 in lifetime fuel savings | $1,000 off the average new vehicle |
Two rows matter most for your next truck. First, the fine row explains why automakers already had room to build what sells. Second, the crossover row moves small SUVs into the car fleet, while pickups stay light trucks.
Why the $0 Penalty Matters More
Congress made the bigger shift in corporate average fuel economy rules a year earlier. Signed July 4, 2025, the One Big Beautiful Bill Act set CAFE civil penalties to $0. Reuters later reported NHTSA told automakers the zero applies back to the 2022 model year.
University of Maryland professor Joshua Linn told Politico the standards now work like a suggestion. In other words, an automaker who misses the target pays nothing. Then in February 2026, EPA repealed every federal vehicle greenhouse gas standard. Those rules were the second push toward smaller engines.
For me, the $0 penalty is the number to watch, more than 34.5. Corporate average fuel economy targets without a fine leave powertrain choices to buyers, gas prices and each automaker’s product plan. Still, Politico expects a court challenge to the new rule, so the target itself is not settled.
V8s, Half-Tons and Heavy-Duty Pickups
Half-ton pickups stay in the light-truck fleet, and body-on-frame 4×4 SUVs likely stay there too. Their targets scale with footprint, the area between the four tires. As a result, a crew-cab Silverado carries a lower mpg target than a compact crossover. Under the proposed Trump fuel economy standards, the light-truck curve rises only 0.25% a year from 2029.
For V8 buyers, the rollback removes pressure without adding engines overnight. GMC, for example, announced new V8s in the 2027 Sierra before this rule. I drive a Colorado ZR2 today, and I have owned five Jeeps over the years. Two were Grand Cherokee Overlands, and I believe both had the V8. Personally, I would rather see engines chosen for towing and trail work than for compliance math.
Heavy-duty 2500 and 3500 pickups sit outside this rule entirely. Instead, they fall under separate heavy-duty pickup and van fuel efficiency standards. NHTSA said in January 2026 it plans to reset those on their own track. GM’s new 8.3L Duramax V8 arrives under those rules too, not the 34.5 mpg target.
Stop-Start and Hybrids Under New CAFE Standards
Auto stop-start lost its main federal incentive in February, before this rule. Specifically, EPA’s greenhouse gas repeal ended all off-cycle credits, including the credit automakers earned for stop-start. With CAFE fines also at $0, keeping stop-start is now a product choice for each automaker.
Hybrids follow the same logic. Toyota’s i-Force MAX hybrid, for instance, earns its place on torque as much as on mileage. We covered the trade-offs in the 4Runner hybrid vs. gas comparison. Expect hybrids to stay where they sell and fade where they only served federal fuel efficiency standards on paper.
Range is where slower mileage gains hit overlanders. A loaded V8 truck or hybrid SUV burns more fuel than its sticker says. For this reason, fuel range planning for remote routes still decides where you camp. A RotopaX 2-Gallon Gasoline Pack, RX-PM mount, and Scepter 5-gallon fuel container stretch your range between stations.
Auxiliary Fuel Range Gear for Overlanders
What This Means for You
If you plan to buy a truck or SUV this fall, do not wait on this rule. It changes little on dealer lots right now. Kelley Blue Book put the average new-vehicle price at $50,089 in August. Meanwhile, DOT claims the Trump fuel economy standards cut $1,000 from the average new vehicle’s cost. Against the KBB average, the claim comes to about 2%. In addition, truck tariffs in 2027 weigh on sticker prices this year, while CAFE fines sit at $0.
Want a V8 or a big six? The rollback lowers the odds of those engines leaving for regulatory reasons. However, gas at $4.47 a gallon pushes the other way. Run your own fuel cost math before you pick the bigger engine. Similarly, if you shop hybrids, buy one for the torque and range you want, not because a rule favors it.
Finally, expect lawsuits. The Sierra Club vowed to fight the rule, the Associated Press reported. Courts will then decide whether the 34.5 mpg target stands.
Final Thoughts
I read these new CAFE standards as a signal more than a shake-up. V8 and body-on-frame lineups face less federal pressure, and buyers keep more choice. Still, the $0 penalty from 2025 did most of the work first.
The trade-off sits at the pump. Lower targets mean slower gains in new-vehicle mileage, and your fuel budget carries the difference while gas sits near $4.50. So before you sign, compare the real-world mpg of the two engines you are weighing.
For most readers, my advice is simple. Buy the powertrain your towing, trail and range needs call for, and ignore the politics on both sides. If fuel cost worries you, a hybrid like the i-Force MAX remains a strong alternative to a big V8. The rollback does not take it off the table. Pick the truck you want to live with, then plan your fuel stops around it.
FAQ
What are CAFE standards?
CAFE stands for corporate average fuel economy. NHTSA sets fleetwide mpg targets for the cars and light trucks each automaker sells in a model year. These rules date to the 1970s energy crisis.
Have CAFE standards been removed?
No. The standards still exist, but the new rule lowers the 2031 target to about 34.5 mpg. Also, Congress set the fine for missing a target to $0 in July 2025.
What is the new fuel economy target for 2031?
NHTSA projects about 34.5 mpg fleetwide for model year 2031, down from 50.4 mpg under the 2024 rule. Real-world mileage runs 20% to 30% lower than the CAFE figure.
Do CAFE standards apply to pickup trucks and SUVs?
Yes. Half-ton pickups count as light trucks, and so do many 4×4 SUVs today. The proposal moves crossovers and small SUVs to the car fleet. Heavy-duty 2500 and 3500 pickups fall under a separate NHTSA program for heavy-duty pickups and vans.
Will the rollback end auto stop-start?
Not directly. EPA ended the off-cycle credit for stop-start in February 2026, so each automaker now decides whether to keep the feature. Many trucks already let you turn it off with a button.