90kph on autoroutes, 80kph when the limit without trailer is 110 and 80kph on other roads where the limit is 80 or 90. You are required to have a carte grise (registration document) for a trailer weighing more than 500kg.
I was looking this exact thing up recently (speeds in FR) and oddly found that there is no different legal limit unless you are over 3500kg total train, when it is 90kph as you say.
The Autoroute website 'suggests' 90 when towing but thats it.
If you could point us at the source of info that would be very helpful.
