There's a difference between a day out and a single journey..
My recent trip from Barcelona to Bilbao, than Andorra and via France and Italy back home to Vienna area has proven that some 200miles or 300km a day is a fair distance for my traveling style. 4000km in two weeks time mainly on B or C roads. I am avoiding highway drives as much as possible. As long as it is not too hot it is fun to drive and there is enough time left for sightseeing, food and restaurants.
