The Chilean was awarded a new two-year contract ahead of start of the new season despite persistent rumours linking Bayern Munich boss Pep Guardiola with a move to the Etihad Stadium next summer.
Pellegrini is aware of the pressure which he is under despite the new deal but insists that he has faith in his team and his methods.
"You can't go two years without winning the title," he told reporters. "It's very important to win it. It's also important to trust when you don't win a title, to trust the work you're doing.
"I am sure we will learn from last season. We have to be a lot more consistent."
Pellegrini is confident that his marquee summer signing, Raheem Sterling, will help City to achieve their aims and prove that he was worth his £49 million transfer fee.
"I am sure, in two or three years, we will see that we paid the correct price for him," the 61-year-old added. "English players are more expensive here as they are fighting with all the other nationalities. It is difficult.
"I didn't say he was worth £100m. I said he could be worth that in a few years' time."
The former Real Madrid coach also believes that captain Vincent Kompany will bounce back from a poor 2014-15 season and play a part in improving City's defensive record.
"I trust a lot in Vincent," Pellegrini declared. "It is always important to analyse why we conceded 38 goals [last season] and more than 35 per cent were from set-pieces so it is important to concentrate on the second balls."
