Valtteri Bottas secured the fastest time of Formula 1 testing so far at Barcelona as Mercedes returned to the top of the leaderboard, while Renault rebounded and Ferrari hit trouble.
Mercedes had topped the times on the opening day of the test with Lewis Hamilton, but languished down the order as it swapped speed for distance and netted 180 laps on Thursday.
After using the longer runs to test the newly-spotted controversial DAS system, Mercedes returned to the top of the order one day later with Bottas on multiple occasions through the morning while notching 65 laps.
He set the fastest lap of the test so far, a 1m16.417s, with just over an hour to go.
Shortly after that he swapped the second softest tyre he set that benchmark on for the softest C5 rubber, and delivered a 1m15.732s just as Nicholas Latifi’s Williams ground to a halt on the main straight and brought out a red flag.
Despite that rapid time, the pace was still three tenths off Bottas’s own pole position from the 2019 Spanish Grand Prix.
One of the teams to make the most of the warmer weather – after representative runs were sparse on a chilly Thursday morning – was Renault.
Having started most of the week’s sessions at least 30 minutes late, Renault was out early this time with Esteban Ocon and covered the highest number of laps it has recorded in any session, with its best time of the test so far and 76 laps completed.
The only drawback for Renault has been damage over kerbs so far. Daniel Ricciardo will take over the car in the afternoon for a race run.
Lance Stroll continued Racing Point’s strong start to testing by taking the third fastest time, a lap within the last hour on the second softest C4 tyre around 0.2s quicker than his time set on the C3 medium tyre.
After a strong spate of running on Thursday, Pierre Gasly handed the AlphaTauri over to Daniil Kvyat who set the fourth fastest time, continuing to rack up laps for the Red Bull-affiliated team.
Speaking of Red Bull, Max Verstappen had a strong start to the morning but a mid-session lull was not followed up by a rapid lap, the team instead focusing on working with the second hardest C2 tyre and racking up the most laps with 86.
Antonio Giovinazzi repeated Alfa Romeo’s modest morning testing pace, with Kimi Raikkonen topping Thursday’s afternoon session. Giovinazzi managed the sixth fastest time, ahead of McLaren’s Carlos Sainz Jr who had a nondescript session while notching the second most laps, tied with Ocon.
After crashing lightly at Turn 5 on Thursday afternoon, Romain Grosjean returned to the wheel of the Haas and set the eighth fastest time, ahead of Sebastian Vettel and Latifi.
Vettel had missed the first day and a half of testing through illness, but had a strong start to the morning where he led the lap count for a significant chunk of the session.
However, his morning then ended just an hour and a half in when his car came to a halt on track and caused a lengthy red flag while it was retrieved.
Ferrari revealed the problem was an engine failure that would have to be investigated back at Maranello, so Vettel was sidelined while work began to fit a replacement.
It was a troubled morning for Latifi and Williams after a strong start to the test. Many of his laps were non-representative install efforts and the car spent a significant amount of time in the garage with the floor off, before the problem ended his session with 44 laps. Williams is another team fitting a fresh engine for the afternoon.