The official FIA documents detailing the Formula 1 upgrades for the Spanish Grand Prix raised intrigue on Friday when Mercedes was shown to have brought no changes to its car.
With the next European phase of the season kicking off as part of a critical run of five races in six weeks, Mercedes had been expected to be on the front foot for Barcelona in terms of changes.
Indeed, Mercedes team principal Toto Wolff had openly talked after the Canadian Grand Prix about there being new parts on board for this race.
"Directionally we seem to be adding performance every weekend and we have new stuff coming also, new parts coming in Barcelona that should help us," he said. "So, I would very much hope that we can continue this positive trajectory."
As subsequently revealed by Motorsport.com, the main element of this upgrade package for Spain was a new floor, which is one of the most critical performance elements of current F1 cars.
Normally, the arrival of new parts would be formally notified to rival teams and the media on Friday morning, when the FIA publishes what is officially known as 'Car Presentation Submissions'.
This document details all the new components that teams are running, as well as featuring an explanation of what the aim of these upgrades is.
This forms part of the requirement of Article 19.1 c) of F1's Sporting Regulations which states: "Each competitor must provide a summary document to the Media Delegate listing the name and brief description of all major aerodynamic and bodywork components and assemblies that have not been run at a previous Competition or TCC (testing of current cars) and are intended to be run at the Competition."
So, the absence of the new floor on the Mercedes submission for Spain pointed to the German manufacturer having perhaps hit a snag and delayed the introduction of its new part.
That is not the case, however, with the team actually going ahead with its new floor.
So how could Mercedes introduce its new floor but not need to notify the FIA of it? The answers lie in the specifics of what Mercedes has changed with the floor, and what the rules demand.
The requirements of Article 19.1 relate entirely to new 'aerodynamic and bodywork' components – so in effect anything that has changed shape or been modified in a new way.
The new floor that Mercedes has introduced is actually a change not in its profile, but purely in weight – as it is simply a lighter version of what has been used up until now.
So, from an aerodynamic perspective, and from the viewpoint of the rules, it is officially identical. This is why the FIA did not need to be notified.
From Mercedes' perspective, however, a weight-saving gain in such a low area of the car should bring a performance uplift – especially at an aero and car-dynamic critical track like Barcelona.