Chelsea, Manchester United and Arsenal have dominated the division in recent years, with Liverpool also established in a 'big four' until Tottenham's breakthrough last term.
Spurs pipped City for the final Champions League place but it is Mancini's men who are expected to mount a strong challenge for glory over the forthcoming campaign.
The Italian, who took charge at Eastlands last December, has spent huge amounts of money strengthening his squad this summer and the recruitment drive shows no sign of abating.
The other top clubs have been comparatively quiet in the transfer window and Mancini believes they are now 'putting pressure' on City because they are fearful.
He said: "Are they scared? I think so. At the moment only Manchester City are buying players.
"But that is normal because Manchester City want to improve and the other teams are just big teams who would like a lot of people.
"All the other teams are trying to put pressure on us because for 10 years there were only four teams challenging for the title.
"This year, there are five. I think all these teams over the years have spent a lot of money.
"Manchester United, Tottenham, Chelsea, Arsenal, Liverpool but now City do. There isn't a difference."
Mancini is confident that City can push on from their achievements of last season and take the title this term.
He said: "We have a big opportunity to win the league if we believe in ourselves and do our jobs. We have improved as a team.
"It depends if we can put together a team in the short time available. In my experience, I know after the World Cup in every country there can be a different situation in the league.
"If you remember a few years ago Manchester City were in the Championship, then it is clear every year we must improve.
"Last year, we fought for fourth place until the penultimate game against Tottenham - the aim this year is to try to win the Premier League. That must be our target."