First of all, adhere to the traffic regulations and the maximum speed limit for the section of road being driven.
We recommend following the instructions of the car manufacturer, roof rack manufacturer and roof tent manufacturer/seller. The lowest speed indicated is the maximum speed you may drive.
In principle, 100-130 km/hr is not a problem.
Of influence is; which roof tent you have, the size of your car and how it is mounted. Weather conditions are of course also of influence. Adjust your speed to what you feel comfortable with and use your common sense. And yes, you might drive a bit slower but that's what holidays are for.
