Carlos Sainz was among four drivers who made testing debuts for their new teams for F1 2025 as the end-of-season Abu Dhabi test wrapped up this year's track action on Tuesday.
The one-day test at the Yas Marina Circuit featured all 10 teams running two cars, one for experienced drivers to conduct 2025 Pirelli tyre testing and the other for inexperienced ones to gain valuable track miles, using this year's tyres.
Ferrari's Charles Leclerc ended the year on top of the timesheet with a best lap of 1:23.510, a second slower than last Saturday's pole time around the same track, with his 2024 team-mate Sainz second - albeit now running in a Williams for the first time.
Two days after the Spaniard ended his four-year Ferrari career with a second-place finish in 2024's season finale, Sainz made his official debut for his new team.
Tuesday was actually Sainz's second outing in Williams' FW46 having gained an initial familiarisation in a private test with his new team on Monday at the circuit as the team completed their second of two permitted 'filming' days this year.
Having been given permission by Ferrari to start the next chapter of his F1 career early, Sainz, who remains contracted to the Scuderia to December 31, ran in plain white overalls and crash helmet.
He completed a mammoth 146 laps during the day.
Nico Hulkenberg also ran in non-branded overalls as the German driver reacquainted himself with the Sauber team, 11 years after first driving for them during a single season in 2013.
Hulkenberg, who ended his Haas career with an eighth-place finish on Sunday, was joined on track by new team-mate and newly-crowned F2 champion Gabriel Bortoleto, who clinched the feeder series title in Abu Dhabi and is making his F1 debut next year as one of four rookies on the grid.
Both new Sauber drivers also comfortably a century of laps, Bortoleto racking up 130 and Hulkenberg 113. Hulkenberg also clocked the fourth-fastest time of the day.
Haas are another team changing their line-up completely, after Hulkenberg's move to Audi-owned Sauber and Kevin Magnussen's exit, and Esteban Ocon began his career at the team on Tuesday too with 119 laps.
Ocon sat out last week's Abu Dhabi GP after coming to an agreement with Alpine so he could take part in this test while they ran his 2025 replacement, Jack Doohan, in his first full race weekend. Ocon's 2025 team-mate at Haas is Britain's Oliver Bearman.
Lewis Hamilton's eagerly-anticipated driving debut for Ferrari will happen sometime in the new year with Mercedes taking the seven-time champion on a farewell tour of various headquarters this week, but the post-Hamilton era at the team has already begun on track.
With George Russell driving one W15, finishing third quickest and 0.2s back on Leclerc, Hamilton's 18-year-old replacement Andrea Kimi Antonelli shared the other one with reserve driver Frederik Vesti.
Antonelli sat out both last weekend's F2 races due to illness but returned to the track in the afternoon running for 62 laps after Vesti completed an initial 55 laps in the car.
Red Bull fielded neither of their 2024 race drivers, world champion Max Verstappen and Sergio Perez, with Yuki Tsunoda instead finally getting his chance to drive the company's senior car.
The Japanese driver's test in the RB20 had been pushed for by his backers, and Red Bull engine partners, Honda, although is not considered a pre-cursor to replacing Perez next next year should the Mexican, as is increasingly expected, lose his seat for 2025.
"It's the first time in the past four years that I have driven a different car. You can physically feel why the RB20 has been fighting for a championship this year, it feels like a very different car to drive," said Tsunoda after his 127 laps.
"We have had a very proactive day today so I am really happy with that. There is still a lot of learning that I have to do but the team have done a great job of preparing such a great run today, it's been such an enjoyable atmosphere in the garage. I feel like the car suits my driving style and I haven't struggled much at all to adapt."
Liam Lawson, who drove for RB as usual on Tuesday, is considered the favourite to replace Perez.
New constructors' champions McLaren rounded off their stunning year with Lando Norris, last Sunday's race victor, and Oscar Piastri sharing one MCL38 and their IndyCar driver Pato O'Ward driving the other.
"I enjoyed being back on track for the morning supporting Pirelli with the development of next year's tyres," said Norris after signing off for the year with 84 laps.
"It's always a useful session to do and it's great to work closely with them on it. It's now time to relax after such an incredible end to the season, the team deserve some well-earned time off before we go again next year."
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