Merc and Ferrari explain mistakes that led to DSQs

AUSTIN, Texas — Engineers from Mercedes and Ferrari say the limited practice time afforded by F1’s sprint format was a contributing factor in the costly setup mistakes they made at the U.S. Grand Prix.

Lewis Hamilton was stripped of his second-place finish at the Circuit of the Americas and Leclerc of his sixth-place finish after both cars were disqualified for excessive wear to the resin plank fixed to the bottom of their cars.

The plank is made of a material that wears away as it skids along the track surface, in part protecting the underside of the car but also allowing the FIA to ensure a minimum ride height is maintained.

Running the car low to the ground can yield more performance from the underfloor aerodynamics, but also runs the risk of inducing potentially dangerous losses of downforce as the car bottoms out.

In order to ensure the cars run in a safe condition, the FIA monitors plank wear by measuring four holes in the plank that must be 10mm deep (+/- 0.2mm) at the start of the race and no less than 9mm deep at the end of the race.

After the U.S. Grand Prix, the depth of the holes was checked on Hamilton’s Mercedes, Leclerc’s Ferrari, Max Verstappen’s race-winning Red Bull and Lando Norris’ McLaren. Only the Mercedes and Ferrari were found to be in breach due to excessive wear to the plank material, leading to their disqualification.

The sprint format, which was used for the fifth time this year over the Austin weekend and features qualifying for Sunday’s grand prix on Friday afternoon, means setup decisions like ride heights have to be made after a single hour-long practice session instead of the usual three practice sessions of a normal race weekend.

Once qualifying starts, the cars enter what is known as parc ferme, which severely limits setup changes and exists to stop teams developing one specification of car for single-lap performance in qualifying and another specification for the demands of a full race distance.

Speaking after the disqualification, Mercedes’ trackside engineering director Andrew Shovlin said the combination of limited practice time and the bumpy surface at the Circuit of the Americas had led to his team’s mistake.

“We are of course naturally very disappointed to lose our podium finish,” he said. “Unfortunately, it is one of the pitfalls of the sprint format where we have a solitary hour of running before parc fermé.

“Without running at a race fuel load in FP1, combined with a circuit as bumpy as this and the parts of the track where the drivers have to put the car during the Grand Prix, have contributed to the higher than expected wear levels. We will go away and learn from this but also take the positives from our experience as a whole.”

Ferrari sporting director Diego Ioverno listed similar reasons for his team’s error, but also cited the change in wind intensity and direction in Sunday’s race.

“The sprint weekend is very peculiar and you have very little time to prepare the car — basically only one session and then you go in parc ferme,” Ioverno said. “It means that moment onwards you cannot touch the car any more. On top of this, Austin is a super nice track but it is extremely bumpy.

“Bumpiness is a difficult topic for drivers and for cars, in the past almost everyone failed the suspension and failed the chassis. We knew it would have been tricky and this is the reason why we also lifted the car throughout FP1, and from our consideration it should have been OK.

“As a matter of fact, it turned out we were anyhow too marginal and also because of the wind that changed direction and had a stronger intensity than what was forecasted, this brought our car to not be legal at the end.

“There is not a lot to say and not a lot in this moment that we can do. With hindsight, rewinding the weekend we may have lifted even more the car but we would have lost performance, and we are here always to try to optimise our own performance.”

Mercedes team principal Toto Wolff added: “Setup choices on a sprint weekend are always a challenge with just one hour of free practice — and even more so at a bumpy circuit like COTA and running a new package.

“In the end, all of that doesn’t matter; others got it right where we got it wrong and there’s no wiggle room in the rules. We need to take it on the chin, do the learning, and come back stronger next weekend.”