Horrible Mileage
 

lately my 94 (3.0 v-6) has dropped to around 10mpg. i put new plugs and air filter in but that didnt help. it has original 106k, any sugestions?

Has anything happened to the truck lately when the mileage dipped? Any work done to it around that time?

O2 sensors are known to cause bad mileage when they go out. Are you getting a check engine light?

i just got it and did the timing belt and water pump, it was getting around 15 mpg and all of a sudden it dropped to around 10 and has a lack of power , it is not a timing issue it was fine after the new belt. no codes and no light on.

I'm not familiar with the 3.0 so I'm really just guessing here. So it was running fine after the timing belt and mileage was around 15 and then it just dropped to 10 for no apparent reason? No performance issues at all? It could be something as simple as a problem with the odo. I had an old Dodge and the odometer would just quit turning for a few miles, then start again. I would think for a 5 mile a gallon drop in mileage you would have to have some kind of power/performance drop. Sorry I can't be more help.