Can I get better fuel mileage

[tlzimmerman]

I'd kill for that mileage hauling grain to the elevator. Our N-14's and cat C-12 in Kenworth T800's all come in right at 5 while working to town and back. I was hoping my ISX would get 6....you give me hope for even more at some point. My 9900i Isn't exactly an aero truck though.