Grooves and ride height issues exacerbated Piastri's problems in Brazil

What went wrong for Oscar Piastri at Interlagos

Oscar Piastri had a tough weekend in Brazil. His sprint crash and 10-second penalty in the race made matters worse. That penalty followed a collision with Kimi Antonelli on the early restart. Yet even without those incidents, Piastri seemed unable to overtake teammate Lando Norris. Norris took both pole and victory.

Speed changed after sprint

Piastri was still fast on Friday. Then the pace subsided. In the sprint, he was competitive and fought for second place. The crash stopped that battle. Later in the weekend, he complained of unusual tyre behaviour. According to him, the soft tyre felt almost no better than the medium. The grip was simply not there properly.

New drainage grooves on the circuit

Organisers had grooves cut into the asphalt at several parts of the circuit. This was done to drain water better after last year's problems. The grooves were not only on straights, but also in places where tyres need grip. That is unusual for this kind of modification.

The grooves had two main effects. First, tyres did not touch the road surface as well. The contact patch became smaller. That caused more slippage and faster wear. Second, it gave teams new tuning problems. The underside of the car became more sensitive to oscillations over the grooves.

Ride height proved crucial

Modern Formula 1 cars get a lot of speed from the airflow under the car. Consistent airflow and a low ride height help with that. Grooves interfered with that stability. If a car rolled over an edge, the wear of the board under the car accelerated. In some teams, that wear became so great that there was a risk of disqualification for an entire race distance.

Teams sometimes had to raise the ride height to avoid risk. That reduces downforce. Less downforce means less grip. McLaren chose to raise the ride height after the sprint as a precaution. That came at the expense of performance. Andrea Stella said Interlagos is very sensitive to ride height, so this track was anomalous in these conditions.

Consequences for Piastri and the championship

All these minor drawbacks put Piastri further behind. The combination of tyre problems and less downforce did not suit his driving style. Lando Norris seems to handle a sliding car better. As a result, he benefited in Brazil. After the race weekend, Piastri is 24 points behind Norris with three races to go.

• Grooves reduce tyre contact and increase wear.
• Grooves cause underflow irregularities and planks wear.
• Higher ride heights give less downforce and therefore less grip.

Piastri acknowledges he needs to learn to adapt. His driving style from the beginning of the season worked well. Now he needs to add more variety to his approach. He hopes that the American circuit in Las Vegas will suit him better again and that he will regain confidence there.