The France international ended his seven-year association with the Emirates Stadium club in the summer when his contract expired, allowing him to join City as a free agent.
Sagna accepts he will face greater competition for a starting role in Manuel Pellegrini’s star-studded squad, with Argentina international Pablo Zabaleta his main rival.
But the 31-year-old, who has sympathy for Gunners fans due to the regular departures from their side in recent years, says it was a risk he was prepared to take.
He told reporters: "I am 31 and this was the right time for me to leave Arsenal. I wanted to see somewhere new, and to boost my career.
"I have left a family club, which I joined when I was very young, and where I have known Arsene Wenger all the time.
"There are differences between Manchester and London as cities, regarding the weather, and between the two clubs.
"But I am now part of a much deeper squad at City, where it's even harder for me to win a first-team place.
"It is fair to say that could pose a risk to my place in the France side. But I'm not taking that into consideration. I feel more powerful than ever.
"It is what I was looking for. I needed it in order to go the extra mile.
"Arsenal are, and remain, a quality side. But I can understand their fans feeling frustrated when they see players moving to other clubs."