Ferrari admits it has to work on perfecting its pitstops after Felipe Massa lost time during its final stop in the German Grand Prix.
The Italian squad decided to switch to a new specification of wheel nut from the British Grand Prix, hoping to get rid of the issues that had marred Massa's chances earlier in the year, and to also improve its speed.
At the Nurburgring, Ferrari made six pitstops of which four were flawless, but Massa lost time in his final stop after a problem with the new wheel nut.
Ferrari's head of track operations Diego Ioverno said the team is still working on improving its pitstop performance.
"Since the beginning of the year we have had various issues with pitstops, which we are currently fixing step by step, knowing that this year, with so many stops, anything can happen and indeed we have seen other teams also experience difficulties in this area," said Ioverno.
"Our issues concerned the car itself and the jig of the tools we use and especially the wheel nuts, where we have had several problems. Silverstone was the first race we ran with a completely new specification of wheel nut, which has been very interesting, because in the British Grand Prix, our pitstops were the quickest in the race.
"Then, in Germany we were again using this new wheel nut, which does work better, but the system is still not perfect and, at Felipe's last tyre change, we lost the connection between the wheel nut and wheel nut gun, which cost us around one and a half seconds. So we have more work to do on perfecting it."