GMC Sierra 4WD
18.5 MPG The 2026 GMC Sierra 4WD is EPA-rated at 18.5 MPG combined (17.3 city / 20.8 highway). Over 15,000 miles a year that is about 811 gallons, $2595 a year in fuel, or $0.173 per mile at $3.20/gal.
Across its full 2020–2026 run it averages 18 MPG, essentially flat across 7 model years.
Running cost at different fuel prices and mileages
The figure everyone actually wants, and the one the EPA does not publish — because it depends on a fuel price no agency will commit to.
| Fuel price | Per mile | 10,000 mi/yr | 15,000 mi/yr | 20,000 mi/yr |
|---|---|---|---|---|
| $2.50/gal | $0.135 | $1351 | $2027 | $2703 |
| $3.00/gal | $0.162 | $1622 | $2432 | $3243 |
| $3.20/gal | $0.173 | $1730 | $2595 | $3459 |
| $3.50/gal | $0.189 | $1892 | $2838 | $3784 |
| $4.00/gal | $0.216 | $2162 | $3243 | $4324 |
| $4.50/gal | $0.243 | $2432 | $3649 | $4865 |
| $5.00/gal | $0.270 | $2703 | $4054 | $5405 |
Every model year
| Year | Combined | City | Highway | EPA fuel cost/yr | CO₂ g/mi | Trims |
|---|---|---|---|---|---|---|
| 2026 | 18.5 MPG | 17.3 | 20.8 | $3850 | 502 | 4 |
| 2025 | 17.8 MPG | 16.4 | 19.8 | $3750 | 514 | 8 |
| 2024 | 17.8 MPG | 16.5 | 20.1 | $3750 | 509 | 8 |
| 2023 | 18.4 MPG | 16.9 | 20.5 | $3625 | 499 | 8 |
| 2022 | 17.3 MPG | 15.6 | 19.9 | $3823 | 522 | 13 |
| 2021 | 17.8 MPG | 16 | 20.7 | $3723 | 511 | 13 |
| 2020 | 18.7 MPG | 16.8 | 21.4 | $3550 | 491 | 9 |
Where a model year offered several engines or drivetrains, the figure is the average across all EPA-tested trims that year — the trim count is shown so you can see how much averaging is involved.
How it compares in its class
Among the 33 standard pickup trucks 4wd models tracked here, the GMC Sierra 4WD ranks 9 on current figures, against a class average of 17.1 MPG.
Closest more-efficient alternatives in the same class: Chevrolet Silverado 4WD (19), Ford F150 Pickup 4WD FFV (19), Jeep Gladiator 4WD (19), Toyota Tundra 4WD (19), Ford F150 Pickup 4WD (19.3).
Tailpipe CO₂ is rated at 502 grams per mile, which works out to roughly 7.5 tonnes a year at 15,000 miles.
Questions
What MPG does the GMC Sierra 4WD get?
The 2026 GMC Sierra 4WD is rated at 18.5 MPG combined by the EPA — 17.3 city and 20.8 highway. Across all 7 model years in the database it averages 18 MPG, ranging from 16 to 24 depending on year and trim.
How much does a GMC Sierra 4WD cost in fuel per year?
At 18.5 MPG and 15,000 miles a year, it burns about 811 gallons — roughly $2595 a year with fuel at $3.20 a gallon, or $0.173 per mile. The EPA's own published annual figure for the 2026 model is $3850.
Has the GMC Sierra 4WD become more efficient over time?
Barely. It sits at 18.5 MPG today against 18.7 in 2020 — essentially flat across 7 model years, with efficiency gains offset by weight and power creep.
Is the GMC Sierra 4WD efficient for its class?
It ranks 9 of 33 in the Standard Pickup Trucks 4WD class on current figures, against a class average of 17.1 MPG. That is 1.4 better than typical for the class.
EPA test figures from fueleconomy.gov. Cost per mile and annual fuel spend are computed at a reference price of $3.20 per gallon — use your own price. Estimates based on official test figures and average fuel prices. Real-world consumption varies with driving style, load, terrain and maintenance.