Teams continued to test at Barcelona for the 6th day in 2 weeks. As some are getting settled, more and more teams set out to do more relevant performance runs and race simulations.
The weather was a bit chilly in the morning, but at least the dry conditions were good enough for decent testing. Initially mainly for reliability and aero checks, but towards noon also focused on performance.
The day before, it turned out that several teams had trouble with the Pirelli tyres. Several teams found their front tyres blistered, especially with the soft compound. Pirelli attributed this to the lack of grip, both caused by the lowish temperatures and the new tarmac. With temperatures slightly lower today, more of such blistering is expected.
Lewis Hamilton got off to be busy start for sure, and by 11:00 it was obvious he and Mercedes were trying to see how the car performs on short runs. The Champion repeatedly improved, and on one occasion saw his time deleted due to running off track, but little over 11:30, he set a 1m18.752s on super softs, at the time nearly a second quicker than Verstappen's best.
A bit earlier, McLaren's Fernando Alonso parked the MCL33 on the escape road at turn 7. At the time, he topped the counter with 46 laps on his tally. An oil leak appeared to be the culprit, after which McLaren went to work to replace the engine.
Following the red flag moment, Hamilton went on to sharpen his time further, before Ricciardo did even better, recording 1m18.357s on the hypersoft as well.
At the end of the day, the session was red flagged early due to a stoppage by Leclerc in the Sauber. However, as announced in the morning, 10 minutes later there was a green flag again, allowing the cars to go out on track to perform a standing start tryout. Teams are drivers were eager to see how much of an influence the halo would be, and if it would prevent drivers to properly see the starting light from some grid positions.