BTW, I tow a 9000-pound, 33-foot travel trailer with a 2010, 2500 Ram, 5.7, 6 speed with 4.10 gears, and a cap. The latter makes a difference. I see you have one. That helps with airflow. I get between 6-8 MPG but I haven't as of yet driven the tac. This year if we get on the road in time. I...