Ferrari expect to run an even better car in front of their home fans at Imola this month after winning the first three races of the Formula One season.
"We have a new package for Imola," technical director Ross Brawn said. "There's no reason why we can't keep on improving, that's the great thing about the stability: you find these increments all the time."
Ferrari have been constructor's champions for the past five years and Michael Schumacher looks set for a seventh drivers' title after taking maximum points so far this year.
The San Marino Grand Prix is on April 25th and Schumacher has won there four times in the last five years.
Brawn said Ferrari remained concerned about certain circuits, such as Hungary and Hockenheim, where rivals might still have a tyre advantage in hot weather.
He recognised that the team could now have the most powerful engine but said Ferrari were wary of Jenson Button's BAR.