How fast can u drive...
 

....with a roof box? I have OEM racks with a Thule Atlantis box and I am afraid to go faster than 80mph.... Should I be concerned? Please advise.

I'm sure Thule has a suggested max speed.

Thule says the maximum is the speed limit, or 85 mph, whichever is lower.

Just be careful driving at those speeds with a roof box if there's a strong cross wind.

Also be careful checking before you switch lanes, my dad once had to swirve quickly on the highway and almost flipped his old ML. it had a full roofrack on.

As you would expect Thule says to observe posted speed limits.... I am curious about the likelihood of wind shearing the box off the roof at higher speeds. Say 85 or 90...

sounds like you really want that baby to fly off. JK seriously, if your going faster than 80 you risk the chance of a speeding ticket which is far worse than all your personables trajecting across the freeway

I am traveling in areas where the speed limit is 70. 10 to 15 over is not to bad.

well, i was intrested in if it would start gettging vibrations an high speeds. however i got 120 miles on it soild... i was very happy to see that. didn't have roof racks or anything thou. just had my sunroof open :)

Well, you could shear the mounts off the box, but you could also break the BMW roof rack, conceivably. I wonder whether it produces downforce or lift?

Thule says to obey speed limits in the US, but in Europe they list 130 km/hr as a maximum for the same product, which is the limit I gave you above (130 km/hr = 85 mph)

Whatever the breaking point is on the box, there are several other safety issues to keep in mind, such as vehicle stability in crosswinds. You should also consider that if you are pushing into a headwind, you should subtract that headwind off the 85 mph limit to determine a safe speed.