Red Bull explain RB21 ‘complete behaviour’ turnaround in late upgrades push

Red Bull has got on top of the “complete behaviour” of the RB21 through its steady upgrade path in 2025, believes chief engineer Paul Monaghan.

The RB21 has won two of the last four races, with Max Verstappen adding two second-place finishes alongside these victories.

Paul Monaghan: The Red Bull RB21 is better

The upturn in performance has come in tandem with Red Bull introducing a steady trickle of updates that have seen revisions to the floor design, engine cover, and front wing.

In Singapore, the front wing change saw the team introduce an “evolution of the design, taking further research to increase the camber of some wing sections to extract more load whilst maintaining flow stability”.

At a circuit traditionally weak for Red Bull in recent seasons, Verstappen claimed a front-row start on Saturday and raced to second, only bested by a stellar performance from Mercedes’ George Russell.

It’s been a season of sporadic performance for Red Bull up until recently, with victories in Japan and Imola strewn in amongst some less-impressive days as Verstappen claimed just five podiums in total from the first 14 races.

But the turnaround in performance has reignited Verstappen’s push for a fifth consecutive Drivers’ Championship, although the 63-point deficit to Oscar Piastri remains daunting with just six race weekends remaining.

What does appear certain is that the Dutch driver is fighting with a much stronger weapon than he was earlier in the year.

“The car is better,” Paul Monaghan, Red Bull’s chief engineer, told the media in Singapore.

“Now the question is, can we challenge the previous order from the high-downforce circuits? We’ll have a go, see how we get on. It should be a bit better.

“The question is, how much?”

The ongoing development of the RB21 is unusual in that it offers increasingly small rewards with just six weekends to go before revolutionary new rules are introduced for F1 2026, but Monaghan believes the car is now close to being in its final form after the introduction of a front wing revision in Singapore.

“We hope to extract a bit more lap time from it,” Monaghan explained. “It’s a subtle revision.

“But as the last one was released [for Zandvoort], more evidence became clear: ‘Oh, we could do this and we could do that.’

“A little bit of capacity was available, so we’ve gone ahead and pushed the button and said, ‘Yeah, we’ll bring that.’”

“It should be the last one for this year. There might be some flap trims for Vegas or something like that, as usual.

“But otherwise, yeah, it’s a little bit of performance, and some great work in the factory, and we’ve got it here.”

More on Max Verstappen’s 2025 title chances:

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👉 Max Verstappen delivers Singapore Grand Prix prediction in pursuit of title

Red Bull has addressed the ‘complete behaviour’ of the RB21

With Monaghan explaining that Red Bull has had the capacity to create the upgrades due to there being a little window of opportunity as the 2026 car has “not yet swamped” the manufacturing group, he believes the updates, including a new floor at Monza, have delivered upon the promise spotted through research and simulation work; something that hasn’t always been guaranteed at Red Bull due to correlation issues over the last two years.

“We delivered pretty much what we expected,” he said.

“There was nothing in there, which sort of said, ‘Oh, my goodness me, look, this is so much better than we expected’.

“It’s behaved itself. What we are getting on top of is the complete behaviour of the car.

“We’ve learned things, we found things, and the combination of the new aero parts or new bodywork surfaces, plus some other stuff, it’s a combination of many little changes, not just one, and we picked up a little bit of pace.

“It’s not massive if you look at lap time isolation over a 60-lap race; it can look a little bit daunting, but corner by corner, it’s really small.”

With Verstappen smelling blood in the Drivers’ Championship, the Dutch driver said he “absolutely” believes Red Bull now has momentum on its side.

“The last three weekends now have been really, really nice,” he said in Singapore.

“I mean, up until that point, we were always throwing the setup left and right because it was just not working.

“Sometimes you had a weekend where it was okay, but now, the last three weekends, it’s been solid. We’ve just been fine-tuning, and that’s exactly what you want throughout the weekend.

“Of course, some layouts will be a bit better for us, some probably a bit more difficult, but the basis of the car is a lot more solid, and I think that is what you need.”

While Red Bull does stand out amongst the top teams for its relentless push on development with the RB21, team boss Laurent Mekies has dismissed any concerns that developments this late into the season could leave it on the back foot for next year, although he did admit that there could be an initial performance cost.

“From a Red Bull perspective, and without looking at the other guys around, I think it was, and is, very important that we get to understand if the project has more performance,” he said, when asked if he’s concerned by how late in the season Red Bull is still rolling out updates.

“It’s important that we get to the bottom of it, because we will elaborate next year’s project, even if the regulations are completely different, with the same tools, with the same methodology.

“It’s very important that we validate, with this year’s car, that our way of looking at the data is correct, our way of developing the car is correct, that produces that level of performance – that will give us confidence in the winter for next year’s car.

“So of course, it comes at a cost, undoubtedly, to the ’26 project. But we feel it’s the right trade-off for us, without judging what the other guys are doing.”

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