The Brazilian has claimed the champions could have won by more than the 3-1 scoreline on Sunday if they had really gone for their cross-town rivals.
Ederson, who conceded the penalty from which United scored, insists defeat could have been more severe for Jose Mourinho's men, suggesting City did not hit top gear.
“We did a great game and got a deserved win,” he said.
“We were way better than United, if we had pushed more we could have got a larger result.”
“Absolutely [we can get better]," he added. "Pep’s in his third season here, it’s my second and I can see the team has a deeper understanding of his ideas.
"If we keep going like this, we can achieve a lot in the future.”
Ederson shrugged off giving away the penalty which Anthony Martial scored to give United a lifeline at 2-1.
"I haven't watched the penalty yet," he added about the incident which saw him bring down Romelu Lukaku. "I tried to retract my hands but had no time to do that.
"There was contact between us but I don't know if it was enough for a penalty.
"It's a quick decision in a moment of the game. I tried to hit the ball, it happens. When a goalkeeper makes a mistake, there is no one to save the goal.
"A striker can miss three or four chances and still score the fifth. It's different for a goalkeeper."
City sit 12 points ahead of United, who are eighth, going into the international break.