[opsdave]

What is your efficiency (mi/kwh) when you are fully loaded with gear? Like with a rack on top, with kayak mounted. What speed do you usually drive at to get those numbers?

The place I usually go boating is about 140 miles each way. There are plenty of DCFC along the way, but if I have to stop like 3 or 4 times each way because of drag, perhaps it's not the best idea to use my Bolt EV. I haven't bought the roof rack yet, so doing some homework now. It would be nice to be able to use the Bolt for these trips.

 

[GetOffYourGas]

I don't travel with a kayak, but I do have a Thule roof box. I get about 200 miles of actual range at 65MPH in the summer (air temperature at least 70F). Interestingly A/C makes no appreciable difference - 70F with just fan or 90F with A/C nets the same range.
With a kayak, I would try to get a cover for the opening, to help keep drag down.

 

[ArcticBlue]

My limited data collection showed a reduction from 4.2 mi/kWh without the kayaks to 3.2 with them (same route and similar summer weather conditions). I stay around 65 mph for the majority of the trip. See this thread for more information.

 

[opsdave]

Thank you. I usually tie my kayak on upside down, to keep the cockpit out of the airstream. This pic is on my old Subie before I sold it.

 

[boltage]

Previous cars:

Round (Yakima) or rectangular (Thule) crossbars with nothing on them => -8% to -10%
With boat on top => -15% to -20%

Bolt:

Aero crossbars (Yakima Corebar) with nothing on them => hard to see a difference, presumably smaller in magnitude than -5%
With boat on top => -15% to -20%