The FIA has begun investigating claims that McLaren may be using an illegal method involving water insertion in their tyres.

This accusation adds to the ongoing technical rivalry between Red Bull and McLaren in the 2024 world championship, following previous disputes over 'mini DRS' rear wings and adjustable T-trays.

According to Auto Motor und Sport, Red Bull suspects that McLaren and possibly other teams are attempting to cool their tyres internally by inserting water via the valves.

"The FIA is already investigating the allegations," reported the German magazine from Interlagos.

Mario Isola, head of Pirelli's F1 division, expressed surprise at the claims when he first heard about them.

"I had to figure out for myself what it was even about and how it worked," he remarked.

Apparently, Red Bull explored this tactic years ago, but the FIA subsequently closed the loophole. Now, Red Bull suspects that former team members, who have since moved on to McLaren and other teams, are possibly reintroducing the technique.

Isola explained, "Some of the water evaporates, some of it remains liquid. This allows the heat to be dissipated more easily into the rim. However, the pressure can no longer be controlled as well with the higher moisture in the tyre. The pressure increases more, reducing performance."

He confirmed he would collaborate with F1's governing body to uncover whether teams are indeed employing this technique. The FIA has not made an official statement on the matter.

Earlier at the Brazilian GP, Max Verstappen commented on the perplexing progress of other teams in race performance in 2024.

"It's actually quite strange," he was quoted as saying by De Telegraaf.

"If you look at our car compared to last year, we really made a step in qualifying and also in terms of race pace. The other teams also made a good step in qualifying, but in the race an even bigger one.

"That's something we find very difficult to understand." body check tags ::