A poor performance against the Italian league leaders has left the club looking at ways to change their approach to big matches after being comprehensively beaten
The Sicilians travelled to Turin having not lost there since 2007, when they were defeated 5-0.
However, their record of three consecutive wins away to Juventus came to an end following goals from Simone Pepe, Alessandro Matri and Claudio Marchisio.
Mangia, whose side are yet to win on the road this term, having lost four and drawn one, believes things need to change on their travels, starting with their approach to games.
"Our away games are starting to become a little frustrating, lets just say that," Mangia told the press after the game.
"We had three big chances in the first half, but we also made mistakes, and when you commit errors then you get punished.
"It's clear we will need to change something as we lost the ball too many times. I am not happy with a number of things as we needed to be more dangerous up front and in the middle."
Palermo remain fifth in Serie A following the loss in Turin.