Terrible Gas Mileage

I have an 84 Ford Ranger with the 2.8 171 V6. The car isn't too bad at all except for the gas mileage. 12 mpg...........I swear we've tested several times. We've changed distributor wires, plugs, air filter, choke pulloff, water pump, oil, oil filters, so hard to remember all the stuff we've tried. Is there any suggestions you could give me as to how I can improve my mileage, this is ridiculous. Any help at all would be appreciated.

Is this 2x2? Change the rear gears is about the cheapest and most positive.

how much would a gear change cost?

Try increasing you rear tire size same gear change only less hassel. Even go to larger rims ie Crown Vic and even more tire choices. Good luk

12 mpg???? I have a 1988 Ranger with the 2.9 V6 and I get around 24 mpg. Something is wrong unless you have a very heavy foot or towing something (ha ha). Changing the rear gears my gain some but not worth the trouble. Increasing tire size sometimes will lower gas mileage due to the increase in friction and power to turn a larger tire. Really have no suggestion, but I have not seen a good reply yet. Good luck.