← all 2018 GMC Sierra K15 4WD trims
2018 GMC Sierra K15 4WD — 6.2L 8-cyl, Automatic 8-spd, 4WD
This 2018 GMC Sierra K15 4WD (6.2L 8-cyl, Automatic 8-spd, 4WD) takes premium gasoline. PREMIUM
17
MPG combined (15 city / 20 hwy)
$4,129
est. fuel cost / year (today’s prices, 15k mi)
524 g/mi
tailpipe CO₂
At today's AAA national average price ($4.68/gal, 2026-07-05) — the EPA's own price/date assumption isn't exposed in the public dataset, so we recompute this from the EPA's MPG figure and a sourced current price.
The EPA lists this trim as premium because that's the fuel the manufacturer specified for its mileage test. Many such engines will run on regular with slightly lower power and MPG — but check your owner's manual to see whether premium is required or just recommended.
Other 2018 GMC Sierra K15 4WD trims
| Trim | Fuel | MPG | Fuel/yr |
|---|---|---|---|
| 5.3L 8-cyl, Automatic 6-spd, 4WD | REGULAR | 18 | $3,167 |
| 5.3L 8-cyl, Automatic 8-spd, 4WD | REGULAR | 17 | $3,353 |
| 4.3L 6-cyl, Automatic 6-spd, 4WD | FLEX-FUEL | 19 | $3,300 |
| 5.3L 8-cyl, Automatic 6-spd, 4WD | FLEX-FUEL | 18 | $3,450 |
EPA fuel type: Premium · class: Standard Pickup Trucks 4WD · engine: 6.2L 8-cyl · transmission: Automatic 8-spd · drive: 4WD · MPG retrieved 2026-07-24.