Does the 1998 GMC Sierra 2500 2WD need premium gas?
Fuel grade varies by trim — see the breakdown below.
| Trim (engine / transmission) | Fuel | MPG | Fuel/yr |
|---|---|---|---|
| 5.0L 8-cyl, Automatic 4-spd, RWD | REGULAR | 15 | $4,150 |
| 5.0L 8-cyl, 5-spd manual, RWD | REGULAR | 15 | $4,150 |
| 5.7L 8-cyl, Automatic 4-spd, RWD | REGULAR | 14 | $4,450 |
| 5.7L 8-cyl, 5-spd manual, RWD | REGULAR | 14 | $4,450 |
| 6.5L 8-cyl, Automatic 4-spd, RWD | DIESEL | 15 | $5,200 |
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.