F1 Testing: Red Bull driver Isack Hadjar surprised by strong performance on first day in Barcelona as George Russell also impressed

Isack Hadjar admitted his surprise at Red Bull's "productive" and "smooth" performance after topping the timesheet at the first day of Formula 1 pre-season testing in Barcelona.

While lap times were not considered overly important as teams ran their all-new 2026 cars - following changes to both power unit and chassis regulations - together for the first time, there had been doubts over how Red Bull would fare as they embarked on a first campaign producing their own engine.

Hadjar, who has been promoted to drive alongside Max Verstappen after impressing for Racing Bulls in his rookie campaign, set a time of 1:18.159s to finish the day just over half a second clear of Mercedes' George Russell.

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Equally, if not more, impressive than Hadjar's leading time was the 107 laps the Frenchman was able to amass, with Liam Lawson adding a further 88 for Racing Bulls, the only other team on the grid using Red Bull's first F1 power unit.

Hadjar said: "It was pretty productive, surprisingly. We managed to do a lot more laps than we expected.

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"Everything went pretty smooth. We had like only minor issues, so it's quite impressive considering it's our first day with our own engine. It was definitely smooth."

Asked specifically about the performance of the power unit, Hadjar added: "Honestly, it's pretty decent for our first day.

"It doesn't feel too far off what I'm used to, at least in my first season, on all of the upshifts, downshifts. That was ok. There's still a few things to tweak around, but it's solid."

Russell impressed by Red Bull

While Mercedes continued their strong start to the year as Kimi Antonelli and Russell combined for 149 laps on Monday, the Briton admitted he was impressed by Red Bull's performance.

Mercedes managed an ominously large total of 67 laps at a filming day at Silverstone last week, which suggested they are very well prepared for a season many see them as favourites for, and maintained that solidity despite being outpaced by Red Bull in Barcelona.

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"We're very pleased with the day but I was pretty impressed with a number of other teams, to be honest," said Russell, having taken over from Antonelli for Monday's afternoon session.

"The Red Bull-powered teams, brand-new power unit, and they're a brand-new team from a power-unit side, and they had a really smooth day with two cars. Audi had some good laps in there as well. Haas did the most laps of everyone with a Ferrari engine."

Russell appeared to suggest there is unlikely to be a repeat of the last time brand-new engines were introduced in 2014, when Mercedes went on to win eight successive constructors' titles after having been well ahead of the rest of the field at the first testing events for that era.

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He added: "It's not quite 2014 vibes of half the grid breaking down and having loads of issues. I think Formula 1 has evolved so much since then and the level is just so high in every single aspect.

"It was pretty impressive to see all the teams on the whole having a lot of laps under their belt on day one."

Antonelli: Mercedes very nice to drive

Antonelli gave a favourable review of the Mercedes W17 as he prepares for his second season with the team.

"It was a very interesting morning, very nice to be back in the car," Antonelli said.

"It's a massive learning. We've been trying to tune the power unit and the car, and obviously this afternoon the car has improved a lot, and it's a constant learning.

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"The car is nice. It's very nice to drive and obviously on the power-unit side it's a bit different to what we had last year, it requires a bit more management but it's all doable.

"On the power-unit side, the team did a really good job and driveability, which was a big question mark, seems to be good so far.

"Obviously, it's early days, and that's why with the running we will discover a lot more about the car and the power unit and we'll be able to see where it's lacking or where it's actually good, but so far, the package is feeling good."

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