The good news for Ferrari is that their SF90 appears to be the car to beat; the bad news is that it is not the most reliable.
Ferrari changed their schedule for Day Seven, putting Charles Leclerc in the car for the entire day after he missed Wednesday's running when Sebastian Vettel crashed.
The second pre-season test has begun with McLaren setting the early pace, while Ferrari and Mercedes have both hit stumbling blocks.
Testing resumed in Spain on Tuesday with Mercedes arriving at the track with a new nose, front wing and floor for their W10.
Antonio Giovinazzi may have set the pace on Tuesday morning in Spain but all eyes were on Mercedes' updates - and Ferrari's minimal of running.