The FIA is satisfied that Mercedes’ new mirror design complies ‘to the letter’ of the rules, despite some intrigue over them at the Austrian Grand Prix.
As part of a major update that the Brackley-based team brought to the Red Bull Ring, Mercedes introduced extra bodywork to help support the outside edge of the W09’s mirrors.
The use of this support caused some controversy, because the rival Ferrari team had been told to remove extra supports that it had fitted to its halo mirrors at the Spanish Grand Prix because the FIA suspected they were delivering an aerodynamic advantage.
As can be seen in the image below, which compares the Mercedes Austria design to what it ran previously, the support was not necessary before.
With the supports having suddenly appeared, suspicions among rivals were that the fins were not actually needed for structural reasons, but were instead primarily aimed at better directing airflow for an aerodynamic benefit.
F1 race director Charlie Whiting was aware of the rumblings about the matter at the Red Bull Ring, but was satisfied that Mercedes had done nothing wrong.
“We are happy with them because they conform precisely to the letter of the TD [technical directive] that we sent,” he said.
“The additional mounting is on the underside of the mirror, so I don't see any issue there at all. If you look at the Force India and the Red Bull they have something similar, but not so far outbound.”
Whiting’s reference to the TD is related to a note that the FIA’s Nikolas Tombazis sent to teams after Spain clarifying the FIA’s position on what teams were and were not allowed to do.
In the TD, Tombazis said: “Whilst we accept that teams will legitimately design the mirrors, housings and mountings to minimise any negative aerodynamic effects they may cause, we believe that any aerodynamic benefits should be incidental, or at least minimal.”
While the extent of an ‘incidental’ benefit is open to interpretation, it is important to note that Tomboazis made it clear that any support should be “mounted to the lower and/or inboard surface(s) of the mirror housing”.
This is exactly what Mercedes and some other teams have done – as the Red Bull design shows below.
Below, Force India’s design also shows how the supports are inboard and below the mirrors.
Additional reporting by Adam Cooper