Revealed: How alleged illegal F1 parc ferme trick works

Ahead of the United States Grand Prix, the FIA has decided to carry out precise checks on F1 cars after concerns were raised that an unidentified team had adopted a system that would allow it to modify the ride height in parc fermé. 

Such a system would be in breach of the technical regulations. Article 40.2 states: "The aerodynamic set up of the front wing may be adjusted using the existing parts. No parts may be added, removed or replaced." 

This is then reinforced by Article 40.9. It states no part of the car can be modified in parc fermé.

The controversy stems from the possibility that one team had developed a system where it could vary the ride height of the bib - or T-tray, as it is sometimes referred to.

Differences in the height of this component allow for pure performance in qualifying or a more measured approach in the race, when the car is laden with fuel.  

Following the Singapore Grand Prix, it is understood frequent contact took place between teams and the FIA's technical department relating to the system which would not necessarily be activated by the driver.

Should such a system be in use, a mechanic could activate it under parc fermé conditions during the usual work post-qualifying, with no observer aware that was the case. 

NOTE: The drawing below is a general description to show where the bib/T-Tray is on a car and is not indicative of any single team.