Mtn bike and kayak hauling

I solved the problem by buying an Oru foldable kayak - it folds up into a large box shape for transport. I can fit both it and my MTB in the hatch with the rear seats folded flat - no eco impact at all!

Folding Kayaks That Go Anywhere | Oru Kayak

 

A hitch mount bike rack on a Prius is not aerodynamic either. Most of the bike sticks out in the direct windstream, not in any protected wind shadow, so is still a big MPG hit.

I use a hitch mount for convenience, as I'm getting too old to hoist numerous bikes atop the roof when supporting cycling events. And my spouse isn't big enough to do roof-top racks at all, but can use hitch racks without assistance.

 

Hitch is the way to go, always! Not only will it allow you almost no change in MPG if you get the aerodynamics set up right on long trips, but it gives you the option to attach all kinds of other things in the future.

 

No, the design is excellent and the structure very rigid.

 

I just ran into an article linking to a Consumer Reports item. While the hitch rack was better than the roof rack, it wasn't by much:

"6. Aerodynamics matter: ... We did fuel-economy tests at highway speed on a Nissan Altima and Toyota RAV4 with a roof rack, a tail-hitch rack, and a rooftop box. Carrying two mountain bikes on the roof had the biggest impact. The Altima lost 13 mpg, going from 46 mpg to 33 mpg. The RAV4 lost 7 mpg, dropping to 32 mpg from 39 mpg.

... The Nissan lost 12 mpg with the bikes on the hitch-mounted rack, while the RAV4 was down only 5 mpg. The bikes stuck out beyond the sides of the sedan, which created extra drag. They were mostly hidden behind the wider, boxier RAV4’s bodywork.

The rooftop box resulted in a 9 mpg decrease for the Altima and a 5 mpg drop for the RAV4.

Overall, the aerodynamic drag doesn’t hurt the more boxy RAV4 as much as the sleeker Altima. "

 

If you're driving a long distance taking the wheels off and wrapping the bikes in a tarp in a way that doesn't leave gaps between the back of the car and the wrapped up bikes can reduce MPG loss to almost nothing. I did it with a 200 pound woodchipper once, built a special hitch mount and everything and drove 1700 miles with no noticeable loss in MPG. I jammed in some kitchen sponges to prevent the package from scratching bumper cover paint.