Christian Horner has said the Red Bull RB21 has seen “almost every single component on the car changed, upgraded, refined and improved” compared to the team’s 2024 challenger.

Red Bull finished last season third in the Constructors’ Championship, and head into the 2025 campaign having tweaked “almost every single surface” when designing the RB21.

Red Bull tease significant RB21 changes with ‘devil in the detail’

After unveiling their 2025 livery at the O2 Arena in London last week, all 10 teams are due to hit the track in Bahrain for pre-season testing on Wednesday as they look to gather vital data ahead of the new season.

While evolution is possible in the final year of this regulation cycle, the likes of Aston Martin have said their 2025 aerodynamic package is “close to 100 per cent new”, while Mercedes also teased significant changes to their approach on the W16.

Red Bull team principal Horner hinted that his team have followed a similar path, saying that the lack of livery change may belie what has changed underneath the surface.

“Well, the RB21 visually to the RB20 looks very similar, but the devil is in the detail,” Horner said, “and almost every single surface, every single component on the car, has been changed, upgraded, refined and improved – so we’ll get a first indication of what we’ve managed to achieve during these next few days testing.”

In terms of evolution on the car, Horner admitted Red Bull looked at cancelling out the “diva” traits on the RB21’s predecessor.

Max Verstappen won a fourth consecutive Drivers’ title, but Red Bull were unable to hold onto the Constructors’ Championship as they were reeled in by McLaren and Ferrari over the course of the year, with Liam Lawson stepping up to replace Sergio Perez this season.

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“RB20, obviously, it won more races than any other car last year in nine Grands Prix and four sprint races, but it was a little bit of a diva at times – and extracting the most out of the car did become problematic,” Horner acknowledged.

“So what we’re hoping for with RB21 is that we have a much wider operating window, that the car is a little more predictable and slightly easier to work with, so we’ll see.

“We’ll get an indication in these early races, but as always, it’s going to be a season of of development from the first race to the last race.”

With three days of testing to come in Bahrain, Verstappen and Lawson completed their allotted filming day running in Sakhir as the RB21 gained its first mileage ahead of the test.

But with set tyres used for the filming day, Horner admitted there was not much that could be gleaned in terms of overall performance from that initial run, though he said the key work of correlating the team’s simulations and real-world data appeared to be positive from its early impressions.

When asked about his early thoughts on the car, Horner replied: “Well, it is so difficult to get a clear read because we’re running on tyres that are very different to what we’ll use officially at the races and the test, so it’s really just making sure that all the data correlates with our tools in the wind tunnel and in the virtual world, which so far seems to be aligning quite nicely.”

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