Mount lower, pack tighter, keep your shapes clean
Getty Images: halbergman
Add a hitch rack and you add drag—it’s air, not weight, that hurts. Drag grows with the square of speed, which ORNL aerodynamic drag work makes painfully clear at highway pace. In winter, the effect stacks with cold losses explained in NREL cold-weather EV analysis, so thermal prep and speed discipline matter more than heroic charging plans. Keep the rolling side honest with correct pressures; the basics live in NHTSA TireWise and they still save miles.
What you’re looking at: a quick table comparing “empty hitch,” “two bikes,” “roof box,” and “both,” with estimated aero hits and one-line packing tips—so you can pick the least wasteful setup for your trip.
Keep mass close to the bumper and out of the slipstream. Strap pedals and wheels, add a soft tie from saddle to arm, and avoid big flat faces to the wind. If you must carry both bikes and a box, bikes on the hitch and box on the roof is usually the cleanest combo—then trim 5–10 mph when the wind’s up.
My Verdict
You control most of the penalty. Mount low, pack tight, and drive a touch slower—your range won’t evaporate before the trailhead.
