2025 GMC Sierra Specs
10 powertrain configurations on federal record for the 2025 GMC Sierra: 3.0L 6-cyl Diesel; 2.7L 4-cyl Regular Gasoline; 5.3L 8-cyl Regular Gasoline; 6.2L 8-cyl Premium Gasoline, in Rear-Wheel Drive and 4-Wheel Drive, rated up to 26 MPG combined by the EPA.
Source: EPA federal records (fueleconomy.gov) · Updated 2026-10-26 · By CarWhere Research
| Engine | Transmission | Drivetrain | City | Highway | Combined |
|---|---|---|---|---|---|
| 3.0L 6-cyl Diesel | Automatic 10-spd | Rear-Wheel Drive | 23 | 29 | 26 |
| 2.7L 4-cyl Regular Gasoline | Automatic 8-spd | Rear-Wheel Drive | 18 | 21 | 19 |
| 5.3L 8-cyl Regular Gasoline | Automatic 10-spd | Rear-Wheel Drive | 16 | 21 | 18 |
| 5.3L 8-cyl Regular Gasoline | Automatic 10-spd | Rear-Wheel Drive | 16 | 20 | 17 |
| 3.0L 6-cyl Diesel | Automatic 10-spd | 4-Wheel Drive | 22 | 26 | 24 |
| 2.7L 4-cyl Regular Gasoline | Automatic 8-spd | 4-Wheel Drive | 17 | 18 | 17 |
| 2.7L 4-cyl Regular Gasoline | Automatic 8-spd | 4-Wheel Drive | 17 | 19 | 18 |
| 5.3L 8-cyl Regular Gasoline | Automatic 10-spd | 4-Wheel Drive | 15 | 19 | 17 |
| 6.2L 8-cyl Premium Gasoline | Automatic 10-spd | 4-Wheel Drive | 15 | 19 | 16 |
| 5.3L 8-cyl Regular Gasoline | Automatic 10-spd | 4-Wheel Drive | 15 | 19 | 16 |
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Frequently asked questions
What engines does the 2025 GMC Sierra have?
4 engines on federal record: 3.0L 6-cyl Diesel; 2.7L 4-cyl Regular Gasoline; 5.3L 8-cyl Regular Gasoline; 6.2L 8-cyl Premium Gasoline, offered with Automatic 10-spd, Automatic 8-spd and Rear-Wheel Drive or 4-Wheel Drive. The full per-configuration table is above.
What gas mileage does the 2025 GMC Sierra get?
EPA combined ratings run 16–26 MPG depending on configuration — the table above shows city/highway/combined for each engine, transmission, and drivetrain.
How do I get the specs for my exact VIN?
These are the federal-record configurations for the 2025 GMC Sierra overall. For one specific vehicle — its exact engine, trim, factory options, and original window sticker — decode the 17-character VIN free at carwhere.com/tools/vin-decoder.
Where does this data come from?
The U.S. EPA's public vehicle dataset (fueleconomy.gov) — the federal record of every US-market configuration since 1984 — refreshed 2026-10-26. Public-domain data; republish with attribution to CarWhere (carwhere.com).