Does the 2020 GMC Sierra 4WD AT4 need premium gas?
It depends on the trim. Some versions take premium and some take regular — check your exact engine/transmission below.
| Trim (engine / transmission) | Fuel | MPG | Fuel/yr |
|---|---|---|---|
| 5.3L 8-cyl, Automatic 8-spd, 4WD | REGULAR | 18 | $3,450 |
| 5.3L 8-cyl, Automatic 10-spd, 4WD | REGULAR | 18 | $3,450 |
| 5.3L 8-cyl, Automatic 6-spd, 4WD | REGULAR | 16 | $3,900 |
| 3.0L 6-cyl, Automatic 10-spd, 4WD | DIESEL | 24 | $3,250 |
| 6.2L 8-cyl, Automatic 10-spd, 4WD | PREMIUM | 17 | $4,550 |
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.
5 trim(s) · EPA FuelEconomy.gov · retrieved 2026-06-14.