The 2025 Miami Grand Prix was not only a spectacle on the track, but also a source of controversy off the track. Red Bull Racing team principal Christian Horner has asked the FIA ​​to investigate the McLaren MCL39 amid concerns about possible technical irregularities. The call comes after McLaren’s dominant performance in Miami, with Lando Norris winning the race and Oscar Piastri finishing third, while Max Verstappen struggled to finish fourth. Horner, who has long been suspicious of McLaren’s sudden speed, was baffled by the FIA’s response, which failed to take immediate action. The situation has further inflamed the rivalry between Red Bull and McLaren and sent the Formula 1 world into turmoil.

Horner’s suspicions centre on McLaren’s cooling systems, specifically the brake calipers and tyre cooling. According to Horner, it is “impossible” for McLaren to control tyre temperatures as effectively with just air, as the rules require. Before sprint qualifying in Miami, Horner was spotted inspecting Piastri’s car, particularly the area around the brake calipers, suggesting Red Bull has been seeking evidence for some time. “We have raised our doubts with the FIA,” Horner said after the race. “McLaren’s performance is impressive, but there are aspects of their car that raise questions.” He pointed to the MCL39’s unrivalled grip in hot conditions, an area where Red Bull has struggled significantly with the RB21.

McLaren’s dominance in Miami reinforced Horner’s suspicions, with Norris leading comfortably while Piastri made a strong comeback after an early confrontation with Verstappen. The RB21 struggled with overheating tyres and balance issues, preventing Verstappen from capitalising on his pole position. Horner suggested McLaren may have a technical advantage outside the regulations, although he did not name any specific infractions. The allegations follow previous tensions, such as the controversy surrounding McLaren’s flexible rear wing for 2024, which was modified following FIA intervention. Red Bull, who also filed complaints at the time, appear determined to expose any potential loopholes in their rivals’ laws.

To Horner’s surprise, the FIA ​​was reluctant to respond. Instead of launching an immediate investigation, the sport’s governing body stated that there was “no concrete evidence” to warrant a formal inspection. The decision left Red Bull frustrated, especially as Horner had hoped for a quick inspection to provide clarity. McLaren team principal Andrea Stella hit back, calling the allegations “baseless” and “an attempt to destroy our momentum.” He insisted that the MCL39 was fully compliant with the regulations and that McLaren’s success was due to hard work and innovation, not to breaking the rules. Norris and Piastri supported their boss, with Norris wryly remarking: “If they want to look, let them come. We have nothing to hide.”

The situation highlights the intense battle between Red Bull and McLaren, who are neck and neck in both the drivers’ and constructors’ championships this season. McLaren leads the constructors’ standings by a significant margin, while Norris and Piastri occupy the top two spots in the drivers’ standings. Verstappen, who is third, has struggled to close the gap, partly due to the RB21’s shortcomings. Red Bull adviser Helmut Marko backed Horner’s call, suggesting the FIA ​​is acting “inconsistently” compared to previous investigations into other teams. He pointed to the need for transparency to ensure the integrity of the sport.

For Red Bull, the situation is urgent. With the Emilia-Romagna Grand Prix approaching, where upgrades to the RB21 are expected, the team is hoping to gain ground. But the focus on McLaren’s car has also drawn criticism. Some analysts believe Horner is trying to distract from Red Bull’s own problems, such as the disappointing performances of Verstappen’s teammate Liam Lawson. Meanwhile, McLaren are enjoying their lead and seem unfazed by the accusations. The FIA ​​is under pressure to take a stand, while fans eagerly await the next phase in this heated rivalry. What started as a race in Miami has escalated into a battle for credibility, innovation and power in Formula 1.