France is the most complicated:
If the weather is dry AND the gross train weight of the outfit is up to 3.5 tonnes:
The maximum speed is 130km/h on autoroutes, 110km/h on dual carriageways, and 90 km/h elsewhere outside built-up areas.
If it's raining these limits reduce to 110km/h, 100km/h and 80km/h, respectively.
If the gross train weight of the outfit exceeds 3.5 tonnes:
The maximum speed is 110km/h on autoroutes, 100km/h on dual carriageways and 80km/h elsewhere outside built-up areas.
Spain is easy:
80km/h on motorways and dual carriageways, 70km/h elsewhere outside built-up areas.
Germany:
80km/h everywhere outside built-up areas unless the outfit fulfills certain technical requirements and has been approved and marked accordingly, in which case the limit is 100km/h.
I hope that helps.