[hotshottt06]

i did a search but couldnt really find what i was looking for..ok i have a 03 yukon with a 6" RCD + 3" body on 35x12.50r20 mud grapps. it has 58,ooo miles with routine oil changes, tire pressure is good. im gettin 9 MPG is this normal?? im not expecting amazing mileage but shouldnt i get 12-14??? i have a K&N intake which didnt help, i drive much more economical and still no change. any suggestions or comments would be greatly appreciated!