Red Bull pushes fresh upgrades as McLaren freezes development

Red Bull has rolled into Mexico City with the only major car update in the pitlane, while McLaren stands firm on its decision to halt development, even at the risk of handing Max Verstappen late-season momentum.

The RB21 features revised cooling inlets, reshaped brake ducts, and tweaks to the floor and edge wings, signs the team is still chasing every tenth as the 2026 rules loom.

"Changes at this point in the season may seem significant, but they don't always translate into big numbers," said Red Bull chief engineer Paul Monaghan. "These are small steps, but they show we’re moving in the right direction."

Monaghan explained that the new parts stem from lessons learned earlier in the year. "This is a combination of several things we've observed since Monza," he said. "We're not talking about anything revolutionary, it’s more about reorganising and improving the layout to create more space under the bodywork."

He admitted the timing wasn’t ideal. "That’s life," he said. "We’re already deep into the 2026 car project, but if we can get something positive for both programs, then it’s worth it." McLaren, by contrast, has completely stopped updating the MCL39, a move team boss Andrea Stella says was deliberate and necessary.

"To win championships, you need a competitive car," he explained. "We carefully evaluated when to switch focus to 2026. Aerodynamically, our car was already highly refined. To gain even a single point of efficiency would have taken weeks, we’d reached a plateau."

Stella believes Red Bull’s continued push may hurt them later. "Perhaps Red Bull had more room to develop because they had problems early in the season and are now focusing more on the 2025 car," he said.

"Maybe they're willing to sacrifice something towards 2026, because they foresee other challenges that year, so they’re saying: let’s focus on 2025."

Those “challenges,” insiders say, likely refer to Red Bull’s new in-house power unit with Ford, a project already rumoured to be behind schedule. Helmut Marko dismissed that suggestion immediately.

"That’s how we’ve always done it," said the Red Bull advisor. "We kept developing the car in 2021 and Max became champion. The next year, with new regulations, we were competitive again."

Still, Stella insists McLaren’s long-term strategy is wiser. "The 2026 project would have been severely compromised if we kept developing," he said. "As constructors’ champions, we already have the least wind tunnel and CFD time. We had to make smart choices. We’d hit our ceiling."

He warned that pushing on might have even backfired. "Sometimes you see teams bring upgrades that make things worse," he said. "These ground-effect cars are extremely sensitive."

Verstappen, meanwhile, admitted his Friday in Mexico wasn’t as comfortable as the timing sheets suggested. Sitting out FP1 for rookie Arvid Lindblad, the Dutchman still led FP2 but sounded uneasy.

"The rest of the time, it was pretty bad," Verstappen said. "The big problem is the long runs. That worries me for the race. You can be fast over one lap, but if you don’t have race pace, it’s hard to win."