Vettel struggled for rhythm during practice
20 October 2017 – Ferrari's Sebastian Vettel believes more performance can be extracted from the SF70H after enduring a difficult start to the United States Grand Prix.
Vettel was unable to match the pace of championship rival Lewis Hamilton, who led both of Friday's free practice sessions at the Circuit of the Americas.
His frustrations were underlined by a big off-track moment in the early stages of FP2, when he lost control of his car at Turn 19 and skated onto the gravel trap on the outside of the corner.
He recovered back to the pits and set the third fastest time of the session, but lamented his car's balance during the post-session interviews.
"Friday didn't work out for me, but Kimi [Räikkönen] was running, the other cars were running, so there's still a lot you can learn," he commented.
"We have to take it as it is from now, make sure the car is in good shape for tomorrow, to get the rhythm, and then I think we should be quick."
When asked about the importance of rhythm at COTA, Vettel added that the increased bumpiness of the track may have hindered his progress.
"It is [important], especially as it's become a bit bumpier this year... I think the ground is quite loose under the track, but that's why it's important to feel comfortable," he said.
"We're missing some laps, but I'm sure that with a couple of successive laps tomorrow I should be better."
Ferrari has decided to change the chassis on Vettel's car overnight, a move already cleared by the FIA, in an attempt to rectify his handling issues.
Räikkönen ended the day sixth fastest in the other Ferrari.