Gulping the Gas

[clayhilldave]

What's with my '89 Ranger 2.9 4x4 ? I get about 15 mpg if I'm lucky. I tuned her up about a year ago, plugs, rotor/cap, plug wires, etc. and even shot some Seafoam through her and I still get the WORST gas mileage for a 6 cyl. motor. I drive about 65 mi. round trip to work and back every day, and I spend about $75 a week in fuel. Any suggestions????

 

[jhammel85]

Is it all highway? What kind of gears are in truck? Big tires can hurt too.