Pellegrini's team brushed aside a Crystal Palace side enjoying one of their best top-flight seasons last weekend.
Manuel Pellegrini expects another difficult test of Manchester City's ability to win a "different" Premier League title race when they face top-six challengers West Ham on Saturday.
The Hammers were unbeaten in eight league games before losing at Newcastle last week and are sixth in the table.
Slaven Bilic's side have been something of a surprise package in a season which has seen the traditional heavyweights struggle to impose themselves on the title race, with Leicester currently behind leaders Arsenal only on goal difference.
Pellegrini's team brushed aside a Crystal Palace side enjoying one of their best top-flight seasons last weekend with a comfortable 4-0 home win.
But City, a point behind the leaders in third place, were beaten at home by the Hammers in September and manager Pellegrini knows they can't take any result for granted at Upton Park this weekend.
"I don't know if the word is surprised. Most of the teams in the Premier League have very good players," Pellegrini said when asked about the strong performances of several unheralded teams this season.
"If you have good players and a good performance as a team I think everyone can beat another team. The difference is very slight between one team and another.
"That gives more importance to the Premier League. We are not only talking about Crystal Palace and West Ham, but I think Leicester are the same way and Everton."
City play Everton in the second leg of their League Cup semi-final next Wednesday, trailing 2-1 from the first meeting.
They were also unable to beat the Merseysiders in the league just over a week ago when the sides drew 0-0 at Eastlands.
City are unbeaten in five league games but have just 43 points -- half the total they managed when winning the title in 2014.
They are unlikely to match the 86 points they managed then or the 89 they accrued when winning the league two years earlier.
Pellegrini expects a lower total to become champions this season, but he won't mind as long as City finish top.
"This is not a normal league. In the last 10 leagues the team who has won it has got over 80 points - maybe that won't happen this time," he said.
"So it's a different league and it's not a case of our team wasting the opportunity to win it. It's a strong league.
"If you win it, it's because you were the best team. It doesn't matter how many points."
City will be strengthened by the return of midfielder Fernandinho following injury and defender Eliaquim Mangala is also back in the squad.
Captain Vincent Kompany, midfielder Samir Nasri and striker Wilfried Bony are all still out.
West Ham's impressive run of form since the end of November -- last weekend's defeat at Newcastle was their first loss in 10 games -- has moved Bilic's side up to sixth and prompted talk of a top four challenge.
Bilic's dealings in the transfer market this month could determine whether they can sustain their challenge, although the Hammers boss has denied he is interested in signing striker Daniel Sturridge from Liverpool.
Sam Byram, the young right-back, has arrived from Leeds, but Bilic concedes the defender has been bought with next season in mind while Mauro Zarate and Nikica Jelavic could leave the club.
Zarate is expected to complete a move to Fiorentina and Bilic admits he will move to bring in a forward if Jelavic leaves as well.
"We are not panicking. We know that we have a couple of players that are injured," he said.
"On the other hand there are a couple of players that may leave the club.
"Maybe Zarate, maybe Jelavic and if that happens, and it may happen, then we are going to try and get one striker."