Growing suspicions of a cunning Formula 1 car ride height adjustment trick under parc ferme conditions has triggered an immediate FIA response from this weekend’s United States Grand Prix, Autosport can reveal.

Sources have revealed that discussions have taken place between several teams and the FIA over recent weeks to discuss concerns that one unidentified outfit may have found a clever way to adjust front bib clearance between qualifying and the race.

Being able to raise and lower the bib, even by a small amount, between qualifying and the race would deliver a noticeable benefit in terms of perfecting the different ride height requirements between a low-fuel single-lap run and the needs for a heavier car over a race distance.

However, making such an adjustment would be a clear breach of F1’s technical regulations that outlaw changes to the aerodynamic configuration of the car – apart from the front wing – once the car is in parc ferme.

Article 40.2 of F1’s Technical Regulations outlines the components that can be changed, and the only changes in terms of bodywork that are allowed are: “The aerodynamic set up of the front wing may be adjusted using the existing parts. No parts may be added, removed or replaced.”

Article 40.9 adds: “A competitor may not modify any part on the car.”

To ensure that teams do not have devices that allow for easy modifications, the rules add: “it must be clear from physical inspection that changes cannot be made without the use of tools.”

Lando Norris, McLaren MCL38, Max Verstappen, Red Bull Racing RB20, Lewis Hamilton, Mercedes F1 W15, George Russell, Mercedes F1 W15, Sergio Perez, Red Bull Racing RB20, the rest of the field at the start

Photo by: Mark Sutton / Motorsport Images

However, the suspicions that have erupted are that a team has designed its car in such a way that it was possible to adjust the clearance of the front bib – also known as a T-tray – through a change of settings inside the cockpit.

This alteration in theory could be easily done by a mechanic during the regular car assessment work that is undertaken between qualifying and the race, and would be undetected to outside observers.

It is understood teams have been alerted to the possibility of this happening through the design details of all cars needing to be uploaded to FIA servers on open-source components – which all competitors have access to.

The FIA has taken on board the concerns of teams about the possibility of such a device and has decided to take action from this weekend’s race in Austin.

But, while the governing body is clear that any such device that altered the front bib under parc ferme conditions would be illegal, it says it has received no conclusive evidence that such a trick has been used by anyone in F1.

However, with immediate effect, the FIA is changing procedures to check on front bib characteristics from Austin – and this could include using seals on any device that is used to alter the T-tray angle.

An FIA spokesman told Autosport: “Any adjustment to the front bib clearance during parc ferme conditions is strictly prohibited by the regulations.

“While we have not received any indication of any team employing such a system, the FIA remains vigilant in our ongoing efforts to enhance the policing of the sport.

Mechanics collect their cars from Parc Ferme after Qualifying

Photo by: Mark Sutton / Motorsport Images

“As part of this, we have implemented procedural adjustments to ensure that front bib clearance cannot be easily modified.

“In some cases, this may involve the application of a seal to provide further assurance of compliance.”

The revelation about a potential trick system in F1 comes ahead of an intense end to the season, with six races remaining and the outcome of both titles closely fought.