Wenger says City cannot handle the pressure of a title race.
He said: "It's been difficult for City.
"They have been outstanding at home. It is away from home they have lost a little bit. Manchester United are surprisingly there in a comfortable position. No one expected them to be. They have not looked absolutely irresistible this year and you could see that again on Monday night against Blackburn. But they managed to win the game.
"If United make it this year it is really down to experience. What I mean by that is that even the other night at Blackburn, when Ryan Giggs came on in the last 15 minutes, you thought they can only win it now because they know how to deal with the money time.
"That means the last 15 minutes in football when it is 0-0. They don't make a mistake and they have that security at the back. They have won so many titles because they are not nervous."