Robinho told FourFourTwo magazine: "I'm not stupid. Of course United is a more famous club in England.
"At City I can help to make a difference. What difference could I have made at a club like United when they can't go any higher? The challenge appealed to me.
"It's a good team, but it's not a great team. If we were a great team then we would be at the top of the league and not in the middle. But I feel we are progressing.
"There is a question of consistency, which has not been good enough this season. We need to get a run of victories and there are good players here. They need to become winners. It's not just about signing big names.
"It's not in my mind to leave the club. When I go on to the pitch I carry the club's shirt in my heart. I want to repay everyone for making me so welcome. Fans have not seen the best of me yet."