2008 GMC Sierra
12 configurations — EPA fuel economy ratings
| Trim / Variant | City MPG | Hwy MPG | Combined MPG | Fuel | Drive | Engine | Transmission |
|---|---|---|---|---|---|---|---|
| Sierra C15 2WD | 15 | 20 | 17 | Regular Gasoline | Rear-Wheel Drive | 5.3L 8-cyl | Automatic 4-spd |
| Sierra C15 2WD | 13 | 18 | 15 | Regular Gasoline | Rear-Wheel Drive | 6L 8-cyl | Automatic 4-spd |
| Sierra C15 2WD | 12 | 19 | 15 | Premium Gasoline | Rear-Wheel Drive | 6.2L 8-cyl | Automatic 6-spd |
| Sierra C15 2WD | 15 | 20 | 17 | Regular Gasoline | Rear-Wheel Drive | 5.3L 8-cyl | Automatic 4-spd |
| Sierra C15 2WD | 15 | 20 | 17 | Regular Gasoline | Rear-Wheel Drive | 4.3L 6-cyl | Automatic 4-spd |
| Sierra C15 2WD | 14 | 19 | 16 | Regular Gasoline | Rear-Wheel Drive | 4.8L 8-cyl | Automatic 4-spd |
| Sierra K15 4WD | 14 | 18 | 16 | Regular Gasoline | 4-Wheel or All-Wheel Drive | 4.8L 8-cyl | Automatic 4-spd |
| Sierra K15 4WD | 13 | 17 | 14 | Regular Gasoline | 4-Wheel or All-Wheel Drive | 6L 8-cyl | Automatic 4-spd |
| Sierra K15 4WD | 14 | 19 | 16 | Regular Gasoline | 4-Wheel or All-Wheel Drive | 5.3L 8-cyl | Automatic 4-spd |
| Sierra K15 4WD | 14 | 18 | 15 | Regular Gasoline | 4-Wheel or All-Wheel Drive | 4.3L 6-cyl | Automatic 4-spd |
| Sierra K15 4WD | 14 | 19 | 16 | Regular Gasoline | 4-Wheel or All-Wheel Drive | 5.3L 8-cyl | Automatic 4-spd |
| Sierra K15 AWD | 12 | 18 | 14 | Premium Gasoline | 4-Wheel or All-Wheel Drive | 6.2L 8-cyl | Automatic 6-spd |