2021 GMC Sierra 4WDFuel Economy & MPG Ratings
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Real-World MPG
Based on 2 owner reports via EPA fueleconomy.gov
Range: 18–26 MPG
Driving mix: City 50% / Highway 50%
Source: EPA fueleconomy.gov “Your MPG” owner submissions. Real-world results vary by driver behavior, conditions, and equipment.
Owner reported MPG for this vehicle averages 21.6 real world MPG based on 2 owner reports. EPA combined rating is 24 MPG.
Trim Comparison
| Trim | Engine | City | Hwy | Combined | Fuel Cost/yr |
|---|---|---|---|---|---|
| Automatic 10-spd | Diesel Diesel | 22 | 26 | 24 | $3,500 |
| Automatic 8-spd | Regular | 18 | 21 | 19 | $3,550 |
| Automatic 8-spd | Regular | 18 | 20 | 19 | $3,550 |
| Automatic 10-spd | Regular | 16 | 22 | 19 | $3,550 |
| Automatic 10-spd | Regular | 15 | 21 | 18 | $3,750 |
| Automatic 8-spd | Regular | 16 | 21 | 18 | $3,750 |
| Automatic 6-spd | Regular | 15 | 20 | 17 | $3,950 |
| Automatic 6-spd | Regular | 15 | 20 | 17 | $3,950 |
| Automatic 10-spd | Premium | 16 | 20 | 17 | $4,800 |
| Automatic 6-spd | Regular | 14 | 20 | 16 | $4,200 |
| Automatic 8-spd | Regular | 14 | 20 | 16 | $4,200 |
| Automatic 10-spd | Premium | 15 | 20 | 16 | $5,100 |
| Automatic 6-spd | Gasoline or E85 FFV | 14 | 18 | 16 | $4,200 |
Based on gasoline at $3.67/gal, 15,000 miles/year
vs. average new vehicle
Environment
- CO₂ Tailpipe Emissions
- 430 g/mile
- Annual Petroleum Consumption
- 14.9 barrels
Specifications
- Engine
- 6.2L 8-cyl
- Transmission
- 10-speed Automatic
- Drivetrain
- 4WD
- Body Style
- Pickup Truck
- GVWR
- Class 2-3 (6,001–10,000 lbs)
Source: EPA fuel economy data & NHTSA vPIC. Specifications reflect the most common trim configuration.
Engine & Efficiency Details
Source: EPA fueleconomy.gov
- Engine Size
- 3L, 6-cylinder
- Efficiency Tech
- Auto Start-Stop
- Fuel Type
- Diesel
Annual Fuel Cost by State
Prices as of week ending May 18, 2026 · Source: EIA
| State | Gas Price | Annual Cost | vs. National Avg |
|---|---|---|---|
| National AvgEPA default | $4.490/gal | $2,806/yr | — |
| California | $5.957/gal | $3,723/yrHIGHEST | +$917 |
| Texas | $3.888/gal | $2,430/yrLOWEST | $-376 |
| Florida | $4.136/gal | $2,585/yr | $-221 |
| New York | $4.522/gal | $2,826/yr | +$20 |
| Ohio | $4.510/gal | $2,819/yr | +$13 |
| Washington | $5.591/gal | $3,494/yr | +$688 |
| Colorado | $4.618/gal | $2,886/yr | +$80 |
| Minnesota | $4.344/gal | $2,715/yr | $-91 |
| Massachusetts | $4.448/gal | $2,780/yr | $-26 |
Calculated at 15,000 miles/year (EPA standard assumption) using 24 MPG combined. Regular gasoline prices. Actual costs vary.
Recall History
Source: NHTSA✓No recalls reported for this vehicle.
Owner-Reported Problems482 complaints
Source: NHTSANHTSA has received 482 owner complaints for the 2021 GMC Sierra 4WD. Top reported issues include engine, power train and electrical system. The data below is sourced from consumer complaints filed directly with NHTSA.
Problems by System / Component
2021 GMC Sierra 4WD problems by category: Engine: 291 complaints, Power Train: 114 complaints, Electrical System: 65 complaints, Steering: 29 complaints, Fuel System: 29 complaints, Brakes: 22 complaints, Advanced Safety (ADAS): 13 complaints, Structure: 10 complaints.
Sample Owner Complaints
Complaint data is sourced from the NHTSA Complaints Database. Reports are filed by vehicle owners and may not reflect confirmed defects. Last updated via NHTSA API.