McLaren clarification prompts tyre pressure move

Speculation about teams cleverly managing tyre pressures has grown over recent races, amid suspicions that some outfits have come up with ways to minimise the impact of mandatory limits laid down by Pirelli.

At the moment, on behalf of Pirelli, the FIA imposes a minimum starting pressure on the tyres, which is measured when the tyres are fitted to the cars.

However, there have been suspicions that some outfits have founds ways to get the pressures down to the optimum operating window for when the cars are running on track.

Various suggestions for what some teams have been up to have been put forward.

One obvious way is for clever heating and then rapidly cooling of the wheels to adjust the air temperature - and therefore pressure - inside the tyre.

More ingenious solutions – such as a double chambered wheel rim that features a small hole between them to allow air to bleed slowly and drop the pressure – have also been hinted at.

McLaren letter

Although having tyres running at a lower pressure is not illegal – as the pressures are above the minimum level when measurements are taken – pursuing such technology to deliver it has prompted cost fears from some teams.

In light of this, McLaren wrote to the FIA recently asking for clarification about the legality of certain design components that could help manipulate tyre pressure.

It is understood that it wanted to know clearly what was and was not allowed before it committed funds to developing them for 2017.

If its ideas were approved by the FIA, it would have opened the door to the team developing its own technology for next year.

However, it is understood that in the response from the FIA – which was circulated to all the other teams – the ideas were rejected.

This included the FIA making it clear that any double wheel rim chamber would be in breach of Article 12.8.3 of F1 Technical Regulations.

The rules states: "A complete wheel must contain a single fixed internal gas volume. No valves, bleeds or permeable membranes are permitted other than to inflate or deflate the tyre whilst the car is stationary."

The impact of the FIA ruling is that if any team had been running a double wheel rim solution this year then it would be clear that it is now against the regulations.

Erasing suspicion

It is understood that in light of the fresh debate about tyre pressures, the issues of how to respond to the situation came up during a meeting of team managers on Wednesday.

In a bid to erase all suspicions about what teams were up to, it has been agreed that Pirelli and the FIA look at a way of setting up a single pressure control system to monitor the pressures at all times.

If the system can be made effective, then it is possible Pirelli will be able to impose a minimum running pressure rather than a minimum starting pressure.

It is understood that Pirelli is willing to develop such a facility if there is a willingness from the FIA and teams for it to be used.