Mexican Grand Prix – The race official stewards at the Autodromo Hermanos Rodriguez have confirmed that they believe the wheel spacers used by Mercedes recently are in conformity with the technical regulations.
Mercedes introduced a new rear wheel spacer at the Singapore Grand Prix, one that was designed to dissipate heat across the axle and wheels by adding holes and grooves to the part. Following the Japanese Grand Prix, Mercedes lodged an inquiry with the FIA’s Technical Department, requesting clarification on whether the part conformed to the rules. Specifically, the regulation in question was: “any specific part of the car influencing its aerodynamic performance must remain immobile in relation to the sprung part of the car.” and whether the wheel spacer broke this rule.
The FIA Technical Department sent correspondence to the team indicating that they believed the part was in conformity, but such correspondence is merely sent as advice, not as a binding agreement or permission. This resulted in Mercedes not running the part for the United States Grand Prix, fearing a protest from Ferrari. However, heading to Mexico, Mercedes have sought clarification from the race stewards, who state that their opinions only carry any weight for this specific event.
The stewards have stressed that, based on the design of the part submitted to the FIA Technical Department, they consider the part legal and would not take any action against the team. However, if the design is changed in any way, it would have to be examined again to ensure conformity.
This decision essentially clears the way for Mercedes to use the part at the Mexican Grand Prix without any fear of any action from the stewards, but this does not stop Ferrari or any other competitors from being able to lodge a protest that goes above the heads of the race stewards, should they feel that the part is in breach of the Technical Regulations.
The ruling from the Mexican Grand Prix stewards states that, in their opinion, the Mercedes part conforms with the FIA’s Technical Department findings that:
“Regarding the legality of the holes in the spacer:
“1. To determine whether the holes have an aerodynamic influence, one has to consider their
size, shape and function. Small holes will tend to have primarily a cooling function, and while
we can at times consider cooling to be an aspect of aerodynamic performance, we feel that
cooling of very localized areas (as in your design) can be acceptable.
“2. The spacer is specifically part of the wheel assembly (as mentioned in Article 12.8.1), so
provided its main function is that of a spacer, we feel that having some localized bleeding of
the flow for cooling can be acceptable. The fact the spacer rotates is inherent in its function, in
much the same way that the wheel rim spokes rotate.
Hence for the above reasons, we consider the spacer geometry you have adopted to be
permissible, although we would reserve [the] right to judge alternative geometries, and to
change this view if (for example) the spacer were to grow beyond its primary function (that of
a spacer) and if the holes were to become big enough to have a more significant