The Blues claimed a 2-1 win over City in the Premier League on Saturday, their second consecutive win over Pep Guardiola's side.
They will face City again in Istanbul on May 29, and Tuchel says his players will be full of confidence for the match.
"It will not change too much no matter what the result was. But surely it is not a disadvantage to us to have this experience in such a short time to have the possibility to beat them twice," Tuchel told reporters, via Goal.
"We know very well that if you play a final, the context is very special. You have to fight for every centimetre and little advantage that you can win that game. Yes, it gives us the true and genuine belief that we can do it because we have already done it.
"We will try to conserve this feeling and momentum for our arrival in Istanbul. We arrive with our target and clear objective to win. The best way to play a final is through confidence and I think we can conserve the feelings from these matches."