Ferrari might already be looking ahead to 2016.
Although the Italian team has taken a big step forward this year, La Gazzetta dello Sport claims boss Maurizio Arrivabene could now have acknowledged that the potential of the current SF15-T car is limited.
"We were unable to change everything in three months," he said, reportedly referring to the time between the end of the Luca di Montezemolo and Marco Mattiacci era and the deadlines for the launch of the 2015 project.
Arrivabene confirmed that the new car has many of the "same limits of downforce and traction as the old one".
"From the beginning of last year, Mercedes has been very, very fast in qualifying," he added.
"They are very strong, and this is an indication to us of where we need to focus our attention for the future.
"Obviously we have improved the car," said Arrivabene, "but we know there are many things that we cannot make work as we would like."
He said the recent Barcelona race, where a major upgrade package was used for the first time, was a key moment for Ferrari.
"When the car goes well there," said the Italian, "it will be enough for all the other races.
"For next year, we absolutely must have a better car for Barcelona."