The Premier League champions have scored 18 times less than league leaders Manchester United so far this year, with their 50 goals making them the league's fifth-highest scorers.
However, the Italian has admitted that he would settle for scoring less if it meant they kept more clean sheets.
"I hope that we can win the next 11 games 1-0 if it is possible because 1-0 is enough if you don't concede a goal," the Irish Examiner quotes Mancini as saying. "But it is impossible that you don't concede a goal every game.
"It is clear, if we are missing 15 or 16 goals now from last year, it is too much because 10 goals are probably six or seven points.
"This is the difference."
City travel to Aston Villa on Monday night.