The $1,300 Question

Every new car in America wears the same sheet of paper in its window. The big number is the price, and everybody reads it. The number with the little gas pump beside it gets less attention, even though you keep paying it for as long as you own the car.

On Monday the Transportation Department finalized a rule that touches both. It lowers the fuel-economy target automakers have to hit to a fleet average of 34.9 mpg by model year 2031, and it says that will take about $1,300 off the cost of a new vehicle. The department's own analysis also finds that the same rule raises what those vehicles spend on fuel by more than $1,600 over their lives, Reuters reported.

Both numbers are real. They measure different things, they land on different people at different times, and the space between them is most of what this rule means for your next car.

What the rule actually says

CAFE, short for Corporate Average Fuel Economy, dates to 1975, and it has never set a minimum for any single car. It sets an average for everything a company sells in a model year, weighted by how many of each it sells. An automaker can sell a thirsty V8 truck as long as enough efficient cars balance it out. Each company's exact target also depends on the size of the vehicles it sells, so the figures below are the agency's projections for the fleet as a whole.

The rule is formally the third Safer Affordable Fuel-Efficient Vehicles rule, or SAFE III; the department markets it as "Freedom Means Affordable Cars." Its 2031 number is a little higher than the 34.5 mpg the department proposed in December and far below the roughly 50.4 mpg the 2024 rule projected for the same year. 3 other changes matter as much as the headline.

Credit trading ends. Companies that beat their targets have been able to sell the surplus to companies that fall short. Credits earned from model year 2028 on can no longer be traded. Credits earned through 2027 can still be sold, and used for up to 5 model years.

The definition of a truck changes in 2030. Most crossovers count as light trucks today, which earns them an easier target. From model year 2030 a vehicle has to qualify as a truck on real payload and towing capability, or on real off-road geometry. The department expects the fleet to flip from roughly 70% trucks and 30% cars to roughly the reverse. That is why the light-truck figure drops to 26.2 mpg that year: the vehicles left in the category are the heavy ones.

It isn't in force yet. Reuters reports it takes effect around early December, after it is published in the Federal Register.

Why 34.9 is not the number on your sticker

CAFE is scored on 2 laboratory test cycles written in the 1970s, and the results are used as they come out of the lab. The window sticker adds tests for high speed, hard acceleration, air conditioning and cold starts, then adjusts the result down to match how people actually drive. The Energy Department's rule of thumb is that real-world fuel economy runs 20% to 30% below the CAFE figure.

Run 34.9 through that and the 2031 target works out to somewhere around 24 to 28 mpg in window-sticker terms. For comparison, the average new vehicle from model year 2024 managed a record 27.2 mpg in real-world terms, according to the EPA, and the preliminary figure for 2025 is 28.1.

Where the fleet stands on the CAFE scale today depends on who is counting. The department says model year 2024 averaged 30.1 mpg. Environmental groups quoted by Reuters say 35.4. Either way, the old rule's 50.4 was a steep climb. This one is a gentle slope at most.

The $1,300, taken apart

The saving is real, but it is narrower than it sounds. The figure in the agency's analysis is $1,289. It is what automakers would have spent on technology to meet the old rule, for a model year 2031 vehicle, in 2024 dollars. 3 parts of that carry a lot of weight.

Model year 2031. This is not a discount on anything in a showroom this fall. It is an estimate of what a car built 5 years from now won't need.

Would have spent. The old rule had already lost its teeth. In July 2025 Congress set the fine for missing a CAFE target to $0, down from $17 for every 0.1 mpg a company fell short, multiplied by every vehicle it sold. California's stricter rules lost their federal waiver the month before, and in February 2026 the EPA dropped its separate greenhouse-gas limits for cars, a decision now being challenged in court. Most of the pressure this rule removes had been removed already.

If it's passed on. The analysis assumes automakers hand the saving to buyers. Whether they do gets decided in showrooms, where the average new vehicle sold for $50,089 in August, according to Kelley Blue Book.

What the money stands for is hardware automakers no longer have to add: more hybrid systems, more stop-start, smaller turbocharged engines, lighter materials and slipperier bodies. Across the industry the agency puts it at $60.6 billion through 2031, and it isn't spread evenly.

General Motors, the country's biggest seller, gets a third of the total by itself.

The other side of the ledger

The same analysis that finds the $1,289 also counts what the lower target costs. It projects that America burns about 4.6% more gasoline through 2050 than it would have under the old rule, and, according to Reuters, that the vehicles covered spend more than $1,600 more on fuel over their lives.

That fuel bill arrives differently from the saving. The $1,289 lands once, on the day of the sale, with whoever buys the car new. The fuel is paid for a tank at a time over the whole working life of the car, often by 2 or 3 different owners.

The lower price goes to the first owner. The higher fuel bill goes to every owner, the first one included.

It also moves with the pump, and the pump has moved. Regular gasoline averaged $4.48 a gallon on Monday, according to AAA, up from $3.13 a year ago, and diesel set a record above $6.50 last week. A saving printed on a window sticker is fixed. A fuel bill is not.

Run your own numbers

The fleet average doesn't decide what you spend on fuel. The car you pick does, and the math takes 30 seconds.

To put the $1,300 in proportion, say you're choosing between a 27-mpg car and a 35-mpg one. At 12,000 miles a year and today's price, the thriftier car saves about $455 a year, which adds up to the rule's whole $1,289 in less than 3 years. At last September's price it saved $318 a year, and took about 4.

You don't even need a calculator. Every window sticker already shows an estimated annual fuel cost, and how much more or less you'll spend over 5 years than with the average new vehicle. It's the second most important number on the paper, and the one most people skip.

The market moved first

Here is the part no rule controls. Hybrids took a record 16% of new-vehicle sales in the second quarter of this year, according to the Energy Information Administration, up from roughly 1 in 10 of the vehicles built for model year 2024. That happened in a year when the fine for ignoring fuel economy was $0.

The looser rules work in the other direction too. Automakers can now sell more of whatever they like without buying credits to cover it: Ram put the 5.7-liter Hemi V8 back in the 1500 last year, and Ford is replacing the all-electric F-150 Lightning with a gasoline range-extended version in 2027. Buyers will get more choice at both ends. Which end sells is up to them.

Who loses: the credit sellers

Credits were the one part of fuel-economy regulation that moved real money between companies. Automakers that beat their targets, mostly EV makers, sold their surplus to the ones that didn't. Tesla booked a record $2.76 billion in regulatory-credit revenue in 2024, across every program and market it sells in. In the second quarter of this year it booked $146 million, down 67% from a year earlier. Rivian booked $164 million in the first half and has signaled that little more is coming.

That money flowed from the companies selling the thirstiest vehicles to the companies selling electric ones. With the fine at $0, nobody needs to buy CAFE credits, and credits earned from 2028 on can't be sold at all. EV makers lose a revenue stream that had helped offset their costs.

What it means for your next car

This fall: nothing on the lot changes because of this rule. The fine has been $0 for more than a year.

From model year 2028: new credits can no longer be traded, and a revenue stream EV makers used to lean on goes with them.

From 2030: crossovers that lose their truck status fall under the tougher car target. With a $0 fine, tougher is a suggestion. A fine set by law can also be reset by law, and that is the one thing that would make any of these targets bite again.

Every time you shop: read the second number on the sticker. The rule sets a fleet average. Your fuel bill comes from one car.

The $1,300 is printed once, on the day you buy. The fuel cost gets printed every week you own the car.