We found it cuts about a mile per gallon off at highway speeds (at a 10 mpg that hurts,) plus, while the bikes pickup more dirt in back, they pick up more hard to remove bugs in front (we removed the seats and but both handlebars on the passenger side). We now carry them on the back ladder, but we have a side entry camper, so our back is free to use. We use a foam block between the first bike and the ladder, a second foam block between the two bikes, and a strap across the bikes from the two rear jacks. Extremely solid on bumpy roads.