Help with low MPGs

[ajbkid]

Our 2005 F-350 is geting around 8 to 10 mpg, town/country driving.
It has 141,000 miles.
The engine performs fine.
It has a new air filter.
Stock tires.

One thing though, it has an enclosed utility bed. the bed probly only weighs 1500 lbs. that cant hurt the mpgs that bad... can it?
if its not the bed, what should i check/change on it?

[timbo2]

Very Nice Looking Truck What Gears Are You Running And Is It A 4x4

[ajbkid]

Originally Posted by timbo2

Very Nice Looking Truck What Gears Are You Running And Is It A 4x4

thank you
not sure on the gears, but yes its a 4X4.