We know that at highway speeds energy efficiency is improved when the air suspension is at the lowest setting, thereby reducing the overall frontal area of the vehicle as measured from the road surface up. What follows is my speculation: When towing a trailer that is taller than the X, raising the air suspension to the highest setting may improve energy efficiency because then the very aerodynamically shaped X will more effectively push the air away from the top of the trailer. In contrast, having the air suspension at the lowest height when at highway speeds will result in more of the upper body of the trailer being exposed directly to the oncoming airstream. I realize that setting the X air suspension on high allows more air to flow underneath the car. But if the trailer underbody is higher off the road than the X underbody, and if by raising the air suspension setting so that the X underbody matches the trailer underbody, would that improve X energy efficiency while towing? It would be relatively easy for an X owner with a camper trailer to test that proposition. I hope someone does.