Jesus Navas and Sergio Aguero both scored twice as City made it six wins from six games at the Etihad Stadium this season, with 26 goals scored in the process.
However, City have won just once away from home, and have been beaten by Cardiff, Aston Villa, Chelsea and Sunderland.
"It's impossible to play better than that," Pellegrini told Sky Sports.
"Away, we don't play so different, but it's different things like a mistake or bad luck, so we don't have all the points we deserve away.
"Here at home, the team not only plays, but scores all the chances, and that's very important.
"I really think we play exactly the same when we play away. Maybe the teams at home are more difficult than when we come here.
"We are working in that sense so we have the same style of play everywhere and we continue in the same way."
Aguero and Alvaro Negredo again impressed up front for City, but Pellegrini was keen to spread the praise around the team.
When asked if City had the best strike partnership in the Premier League, he replied: "I think we have two very good strikers, but we can't forget about Dzeko, who is also a very good player and Jovetic, who is injured.
"I think that, here at home, to score 26 goals in six matches is not easy, but it's the whole team, not just Aguero and Negredo.
"The way the team plays is also very comfortable for them."