in '02 I took my stock '86 with 2.5, ax-5, NP207 with 4.10 gears and 235/75/15 to Ouray and back with 3 adults, canopy and a load of spare parts, tools, camping gear (rolled over the scale at 6,000lbs with a nearly full tank of gas) and 3 spare tires (2 stacked on the spare holder underneath. We used them all!)
Averaged 17 in the mountains and 22 on the flats. (had clutch slave troubles too) It liked 85 octane better than anything higher (LOST power with a tank of hi-test. WTF?)