Why McLaren’s Las Vegas disqualification exposed a hidden weakness in the MCL39. New FIA details reveal an unexpected anomaly on the McLaren MCL39 after its Las Vegas disqualification.

F1 | The Las Vegas disqualification reveals a McLaren detail: here is the anomaly that emerged

Two days after the Las Vegas Grand Prix, new details have emerged regarding McLaren’s disqualification, which came after the FIA detected abnormal wear on the car’s floor. From the very start of the championship, the MCL39 has built a reputation as the strongest technical package on the grid, but at Las Vegas a peculiar detail regarding its plank became evident. The British car has consistently impressed insiders in every area, particularly through its cornering performance, where the platform of the MCL39 remains extremely stable and free of roll thanks to refined mechanical geometry and top-level aerodynamic efficiency.

In the opening rounds of the season, several interesting details about McLaren came to light. One of the most discussed topics was the seat used by Oscar Piastri, equipped with a thermal-insulation system. There was also talk of a tank fitted in the front part of the chassis which, according to rumours, contained dry ice to cool a specific section of the monocoque. The seat sits close to the entry point of the Venturi tunnels and to the front portion of the plank. This suggested that the lower front section of the car was frequently hitting the asphalt, generating heat that was transmitted into the cockpit. From this, many concluded that the McLaren MCL39 was running a forward-focused setup. A heavily front-loaded setup is considered advantageous, as it allows the team to run the car lower to the ground and extract more downforce. Naturally, in such a configuration, the part of the plank that is most stressed and at greatest risk of excessive wear would normally be the front section.

Why is the Las Vegas disqualification considered unusual for McLaren?

The excessive plank wear is undoubtedly linked to a team error in the Sunday setup preparation. However, FIA analysis revealed something surprising: the most significant wear was found at the rear. This means the team did not simply misjudge the ride-height window; other incorrect decisions also influenced the outcome. According to The Race, increasing pressure from Red Bull pushed McLaren to extract every last bit of performance from the MCL39, even if that required accepting higher risks such as the one seen in Las Vegas. In Brazil, for instance, the floor was reportedly extremely close to the limit while still remaining legal.

At Las Vegas, the error developed after a Friday that failed to provide any representative long-run data, leaving the team without essential information. Based on simulations and data gathered on similar circuits, McLaren decided to increase the car’s aerodynamic load and soften the rear suspension. These choices generated intense porpoising, which inevitably caused excessive plank wear. The team then shifted the balance toward the rear, likely also to counter the graining they feared could appear. These decisions proved to be incorrect and ultimately costly for the team, which must now defend itself from a Max Verstappen who is becoming increasingly dangerous in the fight for the championship title.

With Qatar and Abu Dhabi still to come, McLaren now knows the margin for error is gone – and the FIA will be measuring every millimetre of that plank with a magnifying glass.