Why the Fuel Cost Estimates on Car Window Stickers Are So Inaccurate

Car buyers need to check online to get accurate fuel costs because window sticker projections are two years out of date

By Jeff S. Bartlett

As gas prices soared in 2022, it was clear that the fuel cost estimates printed on new-car window stickers weren’t keeping pace, putting shoppers at a disadvantage when researching models at a dealership. In fact, the one- and five-year projected fuel costs that are required to be printed on every sticker are generally two years out of date.

The national average price for a gallon of regular gas has hovered around $4 this week, up from about $3 a year ago, according to AAA. Because of the price surge, we’ve found some projected fuel costs over five years to be off by thousands of dollars for some vehicles we’ve purchased for our test program. (See specific examples, below.)

The printed window sticker estimates are so out of whack because fuel costs used in the calculations are provided two years in advance to automakers by the Environmental Protection Agency. This means the figures for the 2023 model year were compiled in November 2021 and sent to automakers in December 2021, according to an EPA spokesperson. The stickers also use the price for regular gas, even when a model calls for more expensive premium fuel.

To get the most accurate information at the dealership, car buyers need to use their smartphone to access a QR code, which is also printed on each window sticker; it provides direct digital access to more accurate market information. Photographing that code opens fueleconomy.gov—the official government source for fuel-economy information run by the EPA and Department of Energy. The site provides near-current fuel pricing, updated weekly, and an interactive calculator that can be used to predict future costs based on a gas price and vehicle fuel economy.

Consumers also can find projected annual fuel costs for tested vehicles by accessing our model pages at CR’s Cars page. We update our projections when gas prices change by 50 cents per gallon or more. In our testing, we also calculate each vehicle’s overall fuel economy using special equipment.

New-car window stickers, also called Monroney labels, list a vehicle’s miles-per-gallon rating, an emissions rating, a smog rating, and projected fuel costs for one and five years based on data provided to automakers by the EPA, in conjunction with the Energy Information Administration. The window sticker is meant to provide consumers with a full fuel profile so they better understand future costs and the potential environmental implications of driving the car.

In more normal times, when gas supply and prices are generally stable over long stretches, the difference between the printed estimates and those found via the QR code isn’t that significant. But when gas was surging above $5 a gallon, we saw that the real costs can be double what’s indicated on the printed window stickers when assessing test cars purchased by Consumer Reports. With gas prices coming down, we have rerun the analysis; we found that the projections on the window stickers are now closer to reality.

To help consumers understand how a new car might have an impact on air quality, our Green Choice designation highlights the top 20 percent of new vehicles on the market with the cleanest emissions. CR’s Green Choice cars, SUVs, and minivans are indicated in our ratings by a green leaf icon and include gas-powered, hybrid, and electric vehicles. The new Green Choice rating, introduced in early 2021, was developed in collaboration with the EPA’s SmartWay program, which rates vehicles for levels of greenhouse gas and smog-forming emissions.

A sample image showing how fuel costs are depicted on window stickers.

Illustration: EPA

Comparing Our Window Stickers With Reality

We found significant differences in the estimated costs presented on the window stickers from our recently tested cars compared with what owners will really face right now. Below we break down three examples from cars bought within the past month and explain how the figures are generated.

For the sticker, the EPA assumes a car is driven 15,000 miles, and the calculation is based on its combined miles-per-gallon rating, merging city and highway test results. The average miles used in the comparison found in the small print on each label are based on the vehicles for that model year, using a specific gas price.

For the 2022 models, the window stickers state that the average new car gets 27 mpg and costs $6,500 over five years. The 2022 cars cited below use $2.35 price per gallon, despite the fact that the Subaru WRX uses more expensive premium gas.

By contrast, the window sticker for our 2023 Acura Integra says the average new car gets 28 mpg and costs $8,000 over five years based on $3.65 per gallon.

For our calculations below, we rounded the current national gas price averages to $4 a gallon for regular and $4.70 for premium. The calculations were then rounded.

2022 Ford Maverick
EPA’s combined fuel economy: 37 mpg on regular
EPA’s estimated annual fuel cost: $950
EPA’s estimated five-year fuel cost: $4,765
CR’s estimated annual cost at $4 per gallon: $1,620
CR’s estimated five-year cost at $4 per gallon: $8,110 
Five-year difference in window sticker vs. reality: $3,350

2022 Subaru WRX
EPA’s combined fuel economy: 22 mpg on premium 
EPA’s estimated annual fuel cost: $1,600
EPA’s estimated five-year fuel cost: $8,010
CR’s estimated annual cost at $4.70 per gallon: $3,200
CR’s estimated five-year cost at $4.70 per gallon: $16,020 
Five-year difference in window sticker vs. reality: $8,010

2023 Acura Integra
EPA’s combined fuel economy: 32 mpg on premium 
EPA’s estimated annual fuel cost: $1,700
EPA’s estimated five-year fuel cost: $8,500
CR’s estimated annual cost at $4.70 per gallon: $2,200
CR’s estimated five-year cost at $4.70 per gallon: $11,020
Five-year difference in window sticker vs. reality: $2,460

When fuel prices are relatively stable, these labels are a great resource. We saw a dramatic difference in the estimates when prices climbed to $5 for regular gas, putting the window stickers many thousands of dollars off relevant to real-world, five-year projections.

Consider the lessons of 2022 when shopping for a new car: If gas prices climb, it can have a massive impact on your budget, especially with a less efficient model and/or one that requires premium fuel.

Pro tip: Shoppers should use the QR code on the window sticker or fueleconomy.gov to get timely fuel cost estimates.

Editor’s note: This article has been updated to reflect a drop in gas prices.

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