do you have an intake? if you had both of them you would notice a differance. i drove from norfolk va to lakehurst nj to go to school and it took me a whole tank and then about a 1/4 of of a tank to get here and then after i put my intake and throttle body spacer on i can make it there on a full tank with a little to spare

 

2" and 33's

pic in sig

 

see sig...

 

16in susp lift, 3in body, 40in toyos and 20s. all f250 running gear