Ahead of his home grand prix weekend at the Circuit de Barcelona-Catalunya, Sainz finished second in opening practice on Friday before taking fourth in FP2, ending the day three tenths of a second off teammate Charles Leclerc’s benchmark time.
But Ferrari has now revealed that a fuel system issue on Sainz’s car has prompted it to complete a chassis change ahead of Saturday’s running in Spain.
The switch was reported by FIA technical delegate Jo Bauer in his most recent update on Saturday morning, confirming the scrutineering declaration form for the car had been completed after the chassis change.
Ferrari subsequently confirmed that this was “due to a fuel system issue”. There is no penalty or sanction for the chassis change.
Ferrari debuted a number of updates for its F1-75 car on Friday at the Circuit de Barcelona-Catalunya, which Sainz felt had “definitely got potential” as the team looked to get back in contention against Red Bull at the front of the pack.
“We've seen some changes in the behaviour of the car which is good when you bring upgrades, because you want to see some actual changes,” Sainz said.
“So yeah, [I’m] happy to see them working and happy to see them performing. At the same time, I think we didn't do the right steps going into FP2 and we we made ourselves a bit slower.
“We know maybe which direction not to go, and we need to go back into a feeling that I had in FP1 that was better.”
Despite topping the timesheets in FP2 for Ferrari, Leclerc was uneasy about the team’s long-run pace, having complained that his tyres were struggling. He said after FP2 that he hoped Ferrari could “find quite a bit of pace for tomorrow” and that “at the moment, we are just not strong on race pace”.
Sainz is not the only driver to have undergone a chassis change ahead of final practice in Spain on Saturday.
McLaren was forced into switching the survival cell on Lando Norris’s car as a result of damage that was found by the team on the underside of the car after running over the kerbs.
The FIA also confirmed that both Ferrari and McLaren broke the curfew in order to complete the change, each using the first of two exceptions for the season.
