Most aerodynamic cargo box?
 

When you look at most roof top cargo boxes (Yakima, Thule, etc.), most of them are as un-aerodynamic as the vehicles carrying them and would present lower drag if they were mounted backwards. They tend to be wedge shaped with a rounded tapering front end, a broad flat back end, and don't appear to take into consideration the rising air flow coming off the windshield. In college, I used to car top a kayak and use it as a cargo box. It was more aerodynamic than any of the cargo boxes that I've seen on the road. How would you design a cargo box to meld in with the roof line of a car to produce a minimum of additional drag?

Sounds like you have given this topic some thought.

A longer body is by it's proportional nature more aerodynamic than a comparable shorter body. Therefore not only would a longer carrier body be an advantage, but if it actually worked to lengthen the vehicle body there would be a total advantage.

Think of those trailing edge roof spoilers on hatchbacks, what they are doing is making the car body longer, right?

A roof top carrier which cantilevered over the rear roof edge might be the ticket.

I would hang it off the back instead of up top.

It would be easier to get to that way. And could lengthen the vehicle body aerodynamically if done right.

Funny thing, I always notice these roof cargo boxes now for this reason....They're all put on backwards!! I swear I’ll crap my pants if I ever see someone who has it mounted tapered end back. The tapered end is invariably the front of the box, and unless you've been living under a rock, (or you’re not a frequent visitor to Ecomodder.com) we all know that the taper should be in the back. I wonder if the weather seal is different on the front & back which is the reason you never see them turned around by someone who would know better. Some boxes have a flat back, but others have a perfect aero shape, if mounted the other way. I think they should hang off the back as far as structurally possible as well.

Darn it, you beat me to it.
Hitch Cargo Carriers from Proline

Correct.

bondo -

Is that another prototype for commercialization?

CarloSW2

We hope so Carlos. It took King C. Gillette 17 years to get his new safety razor accepted and profit from the sale of the razors. You have to bear this in mind whenever working on getting a product to market.

I am getting some very good numbers with this new cargo box and another type which mounts on the open tailgate. R&D doesn't pay much but you have to do it.

Have a good 4th,

Bondo

Bondo, your designs look awesome !

I have noticed the same thing about roof top cargo carriers for years. They are all backwards.

Even the manufacturers show the carriers mounted the wrong way. Its the old idea that pointy ends are better than blunt ends.

http://www.rei.com/zoom/dd/2ff2112b-...4dfeba.jpg/440