Need to know what mpg's I should be getting?
 

I just bought a 99 ford 7.3, it has a 4 in. turbo back, AFE stage two intake, ats stage one towing tranny and a 6 postion bullydog. Im getting around 14 to 15 on the highway, is that where I should be? It also has a 4 in. lift and 35 in. tires.
any help is appreciated!
Thanks