The Las Vegas Grand Prix was supposed to be one of McLaren’s strongest weekends. Lando Norris finished second on track. Oscar Piastri finished fourth. Both looked set to score important points in the title fight. Hours later, both cars were disqualified for excessive skid block wear. The sudden reversal forced the team into a detailed investigation to understand how two cars fell outside technical regulations at the same time. The findings show a complicated situation shaped by porpoising, missing data and a setup window that reacted badly to the Las Vegas circuit.
What happened in Las Vegas
During post race inspection the FIA found that the plank on both McLaren cars had worn below the minimum 9 mm thickness. Norris had 0.12 mm of excessive wear. Piastri had 0.26 mm. Even though the values were small and in one location, the regulation is absolute. Andrea Stella said: “We verified together with the technical delegate that the measurement of the skid thickness was correct. Even if the excessive wear is relatively minor and in only one location, as it was 0.12 mm for Lando and 0.26 mm for Oscar, the regulation is very clear that the rear skids need to be at least 9 mm at the end of the race in every location.”
The DSQ wiped out a combined 30 points. It also changed the shape of the drivers title fight. McLaren described the situation as unintended. They said they never planned to run the car that low and never tried to gain performance at the cost of legality.
The early signs of trouble
One of the biggest factors in McLaren’s analysis was the onset of heavy porpoising. Stella explained that the issue appeared early and caught the team by surprise. He said: “From the early laps of the race, it was clear from the data that the level of unexpected porpoising would be a concern. We were able to monitor the situation better on Lando’s car using telemetry data, but it was made more difficult on Oscar’s car, after we lost one of the sensors we use to establish the level of grounding.”
That failure meant the team had incomplete information on Piastri’s car during the race. They relied on driver feedback and indirect data to understand the problem. This complicated their ability to judge how much the plank was wearing.
Stella continued: “We realised relatively soon that this level of porpoising was causing a high level of skid wear energy and this is the reason why both drivers started to take remedial actions in various parts of the circuit. Unfortunately, we also saw that, because of the car operating window and the circuit characteristics, most of these actions were not effective enough in reducing porpoising.”
The drivers tried to adjust, they changed lines and modified braking points. In some corners the actions worked whilst in others the car hit harder. The combination created a situation McLaren could not fully control from the pit wall.
The root cause
Stella provided a clear summary of the primary trigger. He said: “The specific cause that led to the situation was the unexpected occurrence of extensive porpoising, inducing large vertical oscillations of the car. The level of porpoising was exacerbated by the conditions in which the car operated during the race, and it was not anticipated based on what we had seen in practice and based on the predictions of the car operating window in the race.”
McLaren believed they played safe. Their setup included extra clearance compared to practice. Stella said: “Based on the data we had acquired in practice, we do not believe we took excessive risks in terms of ride height and we also added a safety margin for qualifying and the race, compared to practice, in terms of clearance to the ground. However, the safety margin was negated by the unexpected onset of the large vertical oscillations, which caused the car to touch the ground.”
He also explained that the nature of the porpoising made it hard to control from the cockpit. He said: “The porpoising condition that the car developed in the race was also a difficult one to mitigate, as even a reduction in speed, an action that in theory should increase clearance to the ground, was only effective in some parts of the track but in others was actually counterproductive.”
This inconsistency meant the team could not rely on simple on track instructions to save the car.
Why Las Vegas created this problem
Las Vegas has long straights, hard braking zones and uneven bumps. It also has rapidly changing track temperatures. McLaren said these elements put the car into a unique operating range they did not see in practice. Stella said: “The conditions we experienced last weekend and which led to the onset of porpoising and excess of grounding, compared to what was expected, are very specific to the operating window of the car in Vegas and the circuit characteristics.”
The combination of porpoising and lost data created the perfect set of conditions for excessive wear. The restricted practice running earlier in the weekend added to the difficulty. McLaren had limited time to test long run behaviours or measure wear rates.
What McLaren will change
The team believes the problem will not follow them to every track. Stella said: “We have a well established and consolidated way of setting up the car and we are confident that this will lead us to an optimal plan for the coming races, starting from the Lusail International Circuit.”
McLaren will still add new checks. They plan to tighten margins on ride height at bumpy circuits. They will adjust their predictive models for porpoising. They also plan to review sensor redundancy after losing the grounding sensor on Piastri’s car.
The goal is simple. Remove risk without compromising performance.
Final view
McLaren’s Las Vegas disqualification came from an unexpected combination of porpoising, missing data and a car that reacted badly to the circuit. Andrea Stella’s detailed explanation shows that the error was not intentional and not driven by performance chasing. It was the result of a setup window that collapsed under real race conditions.
The team accepts the penalty and takes responsibility for the misjudgement. The focus now shifts to preventing a repeat. If they stabilise the car and keep it legal at high speed circuits, the team can recover in the final races. If not, the Las Vegas setback will cost more than lost points. It will cost trust.
