FuelFacts

Does the 1984 GMC C25 Pickup 2WD need premium gas?

Fuel grade varies by trim — see the breakdown below.

Trim (engine / transmission)FuelMPGFuel/yr
4.1L 6-cyl, Automatic 4-spd, 2WDREGULAR14$4,450
4.1L 6-cyl, 2WDREGULAR14$4,450
5.0L 8-cyl, Automatic 4-spd, 2WDREGULAR14$4,450
5.0L 8-cyl, 4-spd manual, 2WDREGULAR13$4,800
5.7L 8-cyl, Automatic 4-spd, 2WDREGULAR13$4,800
6.2L 8-cyl, 4-spd manual, 2WDDIESEL20$3,900
6.2L 8-cyl, Automatic 4-spd, 2WDDIESEL19$4,100
6.2L 8-cyl, Automatic 4-spd, 2WDDIESEL19$4,100
6.2L 8-cyl, 4-spd manual, 2WDDIESEL19$4,100
6.2L 8-cyl, 4-spd manual, 2WDDIESEL18$4,350
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.

10 trim(s) · EPA FuelEconomy.gov · retrieved 2026-06-14.