Mercedes were first out, Andrea Kimi Antonelli leading the running in the W17 on a cool but dry morning before George Russell took over in the afternoon.

Audi, Alpine, Racing Bulls, Red Bull, Cadillac and Haas also ran across the opening day, while McLaren, Ferrari, Aston Martin and Williams remained absent.

Red Bull newcomer Isack Hadjar ultimately set the quickest unofficial time of the day, a 1m18.159s, as the RB22 emerged as one of the most consistent packages in circulation.

Mercedes was also prominent on the timing screens, with Antonelli closest to Hadjar in the morning and Russell ending the day second overall.

Despite the lack of official live timing, leaked data suggested the day was defined less by outright pace than by mileage.

Haas topped that metric comfortably, Esteban Ocon completing 154 laps in the Ferrari-powered car as the American squad logged the most extensive programme of the seven teams in attendance.

 

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Ocon said the priority was simply getting the car on track.

“Feeling good. I think first of all an unbelievable effort from the team to put the car down [on track] at 9.20am this morning – but the car was ready at 9am, we were waiting on better track conditions and a few things that we wanted to be perfect before we went out,” he said.

“From Fiorano testing with Ollie [Bearman] to here, people have climbed mountains to make this car work and it’s been really good.”

Mercedes’ focus was similarly on learning rather than performance. Antonelli described his opening stint as a “very interesting morning” as the team worked through early calibration.

“It’s very nice to be back in the car. It’s a massive learning – we’ve been trying to tune the PU and the car, and this afternoon the car has improved a lot,” he explained.

Alpine also enjoyed solid mileage with Franco Colapinto at the wheel all day, despite triggering the first red flag of the week.

The Argentinian welcomed the chance to finally benefit from a full pre-season. “It’s very different, but of course it is what I was needing in previous years, and to get this mileage, this running and all the learnings this early in the season is very useful,” he said.

For the new or returning projects, the opening day underlined the scale of the challenge.

Audi’s running was cut short after an early stoppage with Gabriel Bortoleto, who managed just 27 laps.

The Brazilian acknowledged the disruption, saying: “It was I would say a bit of a short day… we found a couple of problems that unfortunately put us out of the day from the morning.”

Audi team principal Jonathan Wheatley later confirmed, “We had a technical issue with the car. We spotted it, decided to switch the car off on track.”

Cadillac also faced limitations, splitting running between Valtteri Bottas and Sergio Perez but totalling only 44 laps, with Perez completing just 11 in the afternoon.

Bottas, back on the grid after a year as a reserve, was nonetheless upbeat.

“I really enjoyed getting back on track – this was the first time I drove this car, so it’s just good to be out there,” he said.

Racing Bulls kept Liam Lawson in the car all day, the New Zealander describing the experience as an adjustment phase.

“New cars, new power units and very, very different to drive, so for us [we’re] just adjusting at the moment, but so far all good,” Lawson said.

With security tight and information tightly controlled, Day 1 offered only early hints rather than conclusions.

More representative running is expected as the week progresses, with Ferrari and McLaren set to join the shakedown from Tuesday and teams free to choose three of the five available days at the Circuit de Barcelona-Catalunya.

Results: Formula 1 pre-season shakedown Day 1 (unofficial)