Does the 2020 GMC Sierra 2WD need premium gas?
Fuel grade varies by trim — see the breakdown below.
| Trim (engine / transmission) | Fuel | MPG | Fuel/yr |
|---|---|---|---|
| 2.7L 4-cyl, Automatic 8-spd, RWD | REGULAR | 21 | $2,950 |
| 2.7L 4-cyl, Automatic 8-spd, RWD | REGULAR | 20 | $3,100 |
| 5.3L 8-cyl, Automatic 8-spd, RWD | REGULAR | 20 | $3,100 |
| 5.3L 8-cyl, Automatic 8-spd, RWD | REGULAR | 19 | $3,300 |
| 4.3L 6-cyl, Automatic 6-spd, RWD | REGULAR | 17 | $3,650 |
| 5.3L 8-cyl, Automatic 6-spd, RWD | REGULAR | 17 | $3,650 |
| 3.0L 6-cyl, Automatic 10-spd, RWD | DIESEL | 26 | $3,000 |
| 5.3L 8-cyl, Automatic 6-spd, RWD | FLEX-FUEL | 16 | $3,900 |
The EPA records the fuel each version was tested on. Whether premium is strictly required or just recommended is an owner's-manual detail the EPA dataset doesn't include — so we don't guess it.
8 trim(s) · EPA FuelEconomy.gov · retrieved 2026-06-14.