Re: 2.8 gas mileage
I have a 1985 2.8l in mine, and I average around city and highway 17 - 21mpg. Some of the best things to do is new coil, distributer, wires, plugs, fresh oil/filter, new fuel/air filters (K&N). Also, pull your carb apart and check it for gunk (and spray a can of Carb-Cleaner in it).
Also, after all that is done, try some HIGH octane gas with gas-line antifreeze and run the piss outta it. After all that, your gas milage should pickup (pun intended) alot. I usually run mid-grade gas in my truck, and it seems to do quite well.
Vance - Calgary, Alberta, Canada
1985 4x4 S-10 and 1988 Jeep YJ