2021 GMC Sierra 4WD specs & fuel economy
The 2021 GMC Sierra 4WD is rated 24 MPG combined by the EPA (22 city, 26 highway). That is 32% above the 18.2 MPG average across the 75 EPA configurations in the 2021 Standard Pickup Trucks 4WD class, placing it in the 95th percentile of its class. At 12,000 miles at $3.50/US gallon it costs about $1,750 a year to run.
EPA data snapshot imported 2026-09-06 · United States · US gallons
The 2021 GMC Sierra 4WD has 13 EPA-listed configurations in our 2026-09-06 data snapshot. Listed transmissions: Automatic 10-spd; Automatic 6-spd; Automatic 8-spd. Compare the engine, drive type and fuel ratings below before matching an individual car by VIN.
How the 2021 GMC Sierra 4WD compares in its class
EPA publishes each configuration on its own. Ranking one against every configuration EPA rated in the same class and model year is our calculation from the 2026-09-06 snapshot, not an EPA figure.
- Combined rating
- 24 MPG
- 2021 Standard Pickup Trucks 4WD average
- 18.2 MPG
- Difference
- 32% above average
- Rank in class
- 95th percentile of 75 configurations
- Reference annual energy cost
- $1,750 · 12,000 miles at $3.50/US gallon
The class average covers every 2021 configuration EPA rated in the Standard Pickup Trucks 4WD class, compared in MPG only, so electric and liquid-fuel ratings are never mixed. The reference cost is a fixed assumption for comparison; the calculator below takes your own mileage and prices.
Engine, transmission and fuel economy
All 13 2021 Sierra 4WD configurations EPA rated, each linked to its source record. Combined primary-fuel ratings: 16 to 24 MPG. Missing values remain “Not reported.”
| Engine / transmission / drive | Primary fuel | City | Highway | Combined | Source |
|---|---|---|---|---|---|
| 6.2L 8-cyl · Automatic 10-spd · 4-Wheel DriveEPA engine descriptor: SIDI; Stop-Start | Premium Gasoline | 16 MPG | 20 MPG | 17 MPG | EPA #43105 |
| 5.3L 8-cyl · Automatic 6-spd · 4-Wheel DriveEPA engine descriptor: SIDI; Active Fuel Management | Regular Gasoline | 15 MPG | 20 MPG | 17 MPG | EPA #43107 |
| 5.3L 8-cyl · Automatic 6-spd · 4-Wheel DriveEPA engine descriptor: SIDI; FFV | Regular GasolineFFV | 14 MPG | 18 MPG | 16 MPG | EPA #43108 |
| 3L 6-cyl · Automatic 10-spd · 4-Wheel Drive | DieselDiesel | 22 MPG | 26 MPG | 24 MPG | EPA #43109 |
| 5.3L 8-cyl · Automatic 10-spd · 4-Wheel DriveEPA engine descriptor: SIDI; Stop-Start | Regular Gasoline | 16 MPG | 22 MPG | 19 MPG | EPA #43111 |
| 5.3L 8-cyl · Automatic 8-spd · 4-Wheel DriveEPA engine descriptor: SIDI; with Cylinder Deactivation | Regular Gasoline | 16 MPG | 21 MPG | 18 MPG | EPA #43113 |
| 4.3L 6-cyl · Automatic 6-spd · 4-Wheel DriveEPA engine descriptor: SIDI | Regular Gasoline | 15 MPG | 20 MPG | 17 MPG | EPA #43115 |
| 2.7L 4-cyl · Automatic 8-spd · 4-Wheel DriveEPA engine descriptor: SIDI; 4-mode/Sport transmission | Regular Gasoline | 18 MPG | 21 MPG | 19 MPG | EPA #43196 |
| 2.7L 4-cyl · Automatic 8-spd · 4-Wheel DriveEPA engine descriptor: SIDI; 3-mode transmission (work truck) | Regular Gasoline | 18 MPG | 20 MPG | 19 MPG | EPA #43315 |
| 5.3L 8-cyl · Automatic 6-spd · 4-Wheel DriveEPA engine descriptor: SIDI | Regular Gasoline | 14 MPG | 20 MPG | 16 MPG | EPA #43818 |
| 5.3L 8-cyl · Automatic 8-spd · 4-Wheel DriveEPA engine descriptor: SIDI | Regular Gasoline | 14 MPG | 20 MPG | 16 MPG | EPA #43873 |
| 6.2L 8-cyl · Automatic 10-spd · 4-Wheel DriveEPA engine descriptor: SIDI | Premium Gasoline | 15 MPG | 20 MPG | 16 MPG | EPA #44029 |
| 5.3L 8-cyl · Automatic 10-spd · 4-Wheel DriveEPA engine descriptor: SIDI | Regular Gasoline | 15 MPG | 21 MPG | 18 MPG | EPA #44031 |
Other 2021 GMC Sierra versions
EPA lists these versions separately. The figures above apply to the listing named “Sierra 4WD”; they are not a specification for every Sierra trim.
Electric and alternative-fuel details
EPA #43108
5.3L 8-cyl · Automatic 6-spd · 4-Wheel Drive
- Alternative fuel
- E85
- Alternative-mode combined rating
- 12 MPG
Charging time refers to the reported 240 V setup; it is not a DC fast-charge time. Range and efficiency are test estimates, not a used battery’s measured condition.
What would it cost you to run?
Enter your own mileage and prices — these are assumptions, not live pump prices.
| Configuration | Annual cost | Calculation basis |
|---|---|---|
| 6.2L 8-cyl · Automatic 10-spd · 4-Wheel DriveEPA #43105 | $2,471 | Premium Gasoline operation |
| 5.3L 8-cyl · Automatic 6-spd · 4-Wheel DriveEPA #43107 | $2,471 | Regular Gasoline operation |
| 5.3L 8-cyl · Automatic 6-spd · 4-Wheel DriveEPA #43108 | $2,625 | Regular Gasoline operation |
| 3L 6-cyl · Automatic 10-spd · 4-Wheel DriveEPA #43109 | $1,750 | Diesel operation |
| 5.3L 8-cyl · Automatic 10-spd · 4-Wheel DriveEPA #43111 | $2,211 | Regular Gasoline operation |
| 5.3L 8-cyl · Automatic 8-spd · 4-Wheel DriveEPA #43113 | $2,333 | Regular Gasoline operation |
| 4.3L 6-cyl · Automatic 6-spd · 4-Wheel DriveEPA #43115 | $2,471 | Regular Gasoline operation |
| 2.7L 4-cyl · Automatic 8-spd · 4-Wheel DriveEPA #43196 | $2,211 | Regular Gasoline operation |
| 2.7L 4-cyl · Automatic 8-spd · 4-Wheel DriveEPA #43315 | $2,211 | Regular Gasoline operation |
| 5.3L 8-cyl · Automatic 6-spd · 4-Wheel DriveEPA #43818 | $2,625 | Regular Gasoline operation |
| 5.3L 8-cyl · Automatic 8-spd · 4-Wheel DriveEPA #43873 | $2,625 | Regular Gasoline operation |
| 6.2L 8-cyl · Automatic 10-spd · 4-Wheel DriveEPA #44029 | $2,625 | Premium Gasoline operation |
| 5.3L 8-cyl · Automatic 10-spd · 4-Wheel DriveEPA #44031 | $2,333 | Regular Gasoline operation |
Miles ÷ combined MPG × price per gallon; electric versions use miles ÷ 100 × kWh/100 miles × price per kWh. Plug-in hybrids show gasoline operation only. Maintenance, insurance and depreciation are excluded.
Enter your VIN. Check the car before you buy.
Identify the vehicle free, then choose whether to buy its reported history.
Title brands · Odometer records · Auction history, where reported
No subscription. No charge to check the VIN. Report contents vary by vehicle; applicable tax is shown at checkout.
See what the paid report includes →Use these specs to check a 2021 Sierra 4WD listing
- Confirm the seller’s car is a 2021 GMC Sierra 4WD and which of the 3 listed transmissions it has.
- Check that it takes Premium Gasoline or Regular Gasoline or Diesel on the vehicle’s own fuel label.
- Run the VIN for identity, title and reported history — none of which is in this EPA data.
- Check open recalls on the NHTSA lookup and have the car inspected.
Compare nearby model years
These links match the EPA model name. They do not establish that parts or equipment are interchangeable between years.
Sources reviewed
Open the underlying public source and verify that its scope matches the question you are asking.
Frequently asked questions
What is the gas mileage of the 2021 GMC Sierra 4WD?
The 2021 GMC Sierra 4WD is rated 24 MPG combined by the EPA (22 city, 26 highway). That is 32% above the 18.2 MPG average across the 75 EPA configurations in the 2021 Standard Pickup Trucks 4WD class, placing it in the 95th percentile of its class. At 12,000 miles at $3.50/US gallon it costs about $1,750 a year to run.
What transmission does the 2021 GMC Sierra 4WD have?
EPA records list Automatic 10-spd; Automatic 6-spd; Automatic 8-spd across the 13 rated configurations of the 2021 GMC Sierra 4WD. These are model-level configurations. Match the individual car’s VIN and factory build information before identifying a replacement transmission.
What fuel does the 2021 GMC Sierra 4WD use?
The 2021 GMC Sierra 4WD is listed with Premium Gasoline, Regular Gasoline, Diesel, and some versions also list E85 as an alternative fuel. Match the particular configuration and follow the vehicle’s fuel label and owner’s manual.
How much does the 2021 GMC Sierra 4WD cost to run per year?
About $1,750 in fuel or energy at 12,000 miles at $3.50/US gallon, using the 24 MPG combined EPA rating. That excludes maintenance, insurance, depreciation and charging-session fees. Enter your own mileage and prices in the calculator on this page for a figure that matches your driving.
Are these the exact specifications of my Sierra 4WD?
These are the 13 EPA model-year configurations recorded for the 2021 GMC Sierra 4WD, not a decode of an individual VIN or a complete trim catalogue. Confirm identity, installed equipment and service requirements with the car’s VIN and manufacturer records.
Will I achieve the listed fuel economy?
EPA ratings support comparisons under standardized test conditions. Your result depends on driving, weather, tyres, load, charging pattern and vehicle condition. The cost calculator uses the listed combined rating and your entered prices.