GMC
Sierra 4WD AT4X
U.S. fuel economy and specifications from the EPA.
19Best combined MPG2024 model year
2023–2026Model years4 with EPA ratings
6Rated configurationsDrive, transmission and engine
3–6.2 LEngine sizeDisplacement
Best combined MPG by model year
The highest EPA rating among each year's configurations.
2023 15 MPG
2024 19 MPG
2025 19 MPG
2026 15 MPG
1 configuration.
4-Wheel Drive · Automatic 10-spd
Premium gasoline · Standard Pickup Trucks 4WD
- Combined MPG
- 15
- Engine displacement
- 6.2 L
- Cylinders
- 8
4-Wheel Drive · Automatic 10-spd
Diesel · Standard Pickup Trucks 4WD
- Combined MPG
- 19
- Engine displacement
- 3.0 L
- Cylinders
- 6
4-Wheel Drive · Automatic 10-spd
Premium gasoline · Standard Pickup Trucks 4WD
- Combined MPG
- 15
- Engine displacement
- 6.2 L
- Cylinders
- 8
2025 EPA test-car reference
Engine ratings from the EPA test-car reference.
| Engine rated hp | Displacement | Transmission | Drive |
|---|---|---|---|
| 305 | 3.0 L | Automatic · 10 gears | 4-Wheel Drive |
| 420 | 6.2 L | Automatic · 10 gears | 4-Wheel Drive |
4-Wheel Drive · Automatic 10-spd
Premium gasoline · Standard Pickup Trucks 4WD
- Combined MPG
- 15
- Engine displacement
- 6.2 L
- Cylinders
- 8
4-Wheel Drive · Automatic 10-spd
Diesel · Standard Pickup Trucks 4WD
- Combined MPG
- 19
- Engine displacement
- 3.0 L
- Cylinders
- 6
4-Wheel Drive · Automatic 10-spd
Premium gasoline · Standard Pickup Trucks 4WD
- Combined MPG
- 15
- Engine displacement
- 6.2 L
- Cylinders
- 8