Is F1’s water cooling tyre trick paranoia or a real battleground?

In a Formula 1 season dominated by technical intrigue between the top squads, attention was grabbed at the Brazilian Grand Prix by suspicions over a potential trick involving the internal water cooling of tyres.

The speculation follows hot on the heels of wild rumours we have seen throughout 2024 of asymmetric braking systems, flexi front wings, McLaren’s ‘mini-DRS’ and Red Bull’s front bib adjuster as the battle between F1’s big teams gets ever more intense.

One of the games played when performance closes up at the front is to try to hold back the performance of your main rival through politicking, rather than waste effort trying to pursue something similar – which would cost a lot more resource.

This latest story revolves around questions Red Bull has had over whether some teams might be adding a very small quantity of liquid when inflating their tyres, in order to help control temperatures.

While the accusations are centred on several unidentified teams – sources suggest that Red Bull’s main interest involves closest rival McLaren – which has denied any behaviour like this.

It comes with Red Bull being well versed in the tactic, because it is understood to have employed it in the past before doing so was outlawed in an FIA technical directive a few years ago.

However, this is where the matter could fall into a bit of a grey area because TDs are only advisory – and it is ultimately down to the stewards to interpret the wordings of the regulations as they see fit to determine if teams have breached the rules.

And in this case, F1’s technical rules regarding tyre treatment only detail the removal of moisture from the tyres – not adding it.

Article 10.8.4 states:
a. Tyres may only be inflated with air or nitrogen.
b. Any process the intent of which is to reduce the amount of moisture in the tyre and/or in its inflation gas is forbidden.

So in theory, inflating the tyres with moist air does not appear to be strictly prohibited.

From Pirelli’s perspective, it supplies the teams with tyres that are inflated with ‘dry air’ inside.

Head of car racing and F1 Mario Isola said: “We have a dryer connected to our system, and they get all the tyres with dry air, as in the regulation. In the technical directive, it’s written that any modification to this is forbidden, and it’s quite clear.”

Red Bull however…