I have a big family, so we're thinking of installing a Roof Rack. Anyone notice an MPG hit with the rack? What about with the cargo box? These cargo boxes are looking sleeker these days which could indicate better mpg. I believe I saw somewhere there's a 1-2 mpg hit for sure with the rack, but otherwise what are other people's experience? Also, I want to find one that is not structurally bad for the Prius. I've seen racks that go horizontal (from side-door-to-side-door) and vertical (from front windshield to pack). I notice also that rubber cover on the roof that might provide some sort of roof rack support, but I'm unsure exactly what that is? Does the orientation of the roof rack matter? Thanks for your collective help!
Toyota provides their OEM roof racks, and I believe the cargo boxes also. I've got the racks from the OEM store, and bought a cargo box elsewhere. Expect a 2MPG hit at moderate speeds...
Have you considered installing a hitch receiver and one of those hitch cargo carriers? They look something like this: I'm thinking that you wouldn't take as big of an MPG hit, and you can use the hitch for other things like towing a VERY SMALL garden trailer or a bike rack. You'll take an MPG ding, but it won't be as pronounced. Say.....200 bucks for the receiver and another 50 for the cargo carrier. You'll save that much in gas..... GOOD LUCK!
In my experience with a 2005 Prius and a Yakima Skybox, the mpg hit is almost 20% (substantial). These trips have mostly been to Utah and Wyoming mountains from southern California, and I have driven the same route with and without the skybox (which looks like a photon torpedo from the starship enterprise). I really like the skybox, but you'd get better mileage from a rear hitch unit.
