So, I wanted to try and get a good, real world linger mileage comparison of the impact having a bike rack on the back of the car makes to range. As we all know there are so many things that affect range this is difficult to do.
Well, the last two weekends I made one night trips to the same destination about 280 miles away and back. The weather was more or less the same, left the same time of day each direction, etc… The first weekend, I had my 1UP rack (hitch mount) with two mountain bikes on it. The second weekend, I did not.
I’ve included some photos of the tripometer in the car and also the charging screen in the Tesla app to help visualize how much more energy was used but here’s the details and what I did.
Trip 1 - with bikes in tow: I set the cruise to 75 MPH. You can FEEL the bikes dragging as you drive the car. There were moments when I’d bump it up to 80 for a little bit, but for the most part I was at 75 MPH. I averaged 457 Wh/mi and consumed a total of 283.1 kWh over the 619.9 miles. This trip had a few more miles than the next, because I drove through town to the trailhead. If that had any impact at all, it pulled the average down.
Trip 2 - no bikes: For this trip I set the cruise to 85 MPH (10 MPH faster) and left it there the entire trip. Car felt like it should and does on every other trip. Despite going 10 MPH faster, I averaged 361 Wh/mi and consumed a total of 211.6 kWh over the 585.6 miles.
I wish I had the patience to do the exact same speed on both trips, but I honestly don’t think I’d have enough battery to make it between the two superchargers with the bikes at 85 MPH, and I couldn’t bare going 75 MPH without the bikes - I’m in too big of a hurry.
It was interesting to me though to see that despite a 13% increase in speed the car use <79% as much power. I’d guess at highway speeds you’re looking at a 40% range penalty for hitch mounted bike racks.