Board Thread:Naruto Discussions/@comment-25977287-20150704114842/@comment-26005711-20150705201423

Minato's fighting style is to surprise opponents, and he is the type of Shinobi who quickly ends the fight, so he hasn't time to waste to collect Natural energy. That's why he doesn't stay in Sage mode for a long time. And he doesn't have enough experience in Sage mode too.