The Mercedes W13 that took to the track in Sakhir on Thursday differs significantly from the version that was deployed in Barcelona for the first pre-season test two weeks ago.
Looking at the car in detail, the sidepods have undergone profound streamlining, chiefly in their front section. The team's engineers, under the direction of Mike Elliott and design chief John Owen, have rotated the front section of the sidepods by 90 degrees, including the air intakes that feed the cooling system.
In Barcelona, these were square-shaped and placed at the top, while now they are narrow and develop vertically. The front section has thus been drastically reduced in size, with the radiators unconventionally located inside, with minimum inclination with respect to the horizontal axis.
The goal was undoubtedly to free the airflow that skims the bottom, not only to reduce drag, but above all to increase the downforce generated by it.
Two-pronged approach shows Mercedes' capabilities
The visible - and inevitable - consequence of the reduction in size of the upper section of the sides was the appearance of large heat dissipation slits, both in the upper front part of the sidepods and on the hood covering the power unit.
The work carried out by the Mercedes aerodynamicists is not only striking for the extreme reduction in sidepod volume, but above all, it highlights that Mercedes have once again demonstrated the ability to pursue two very different aerodynamic concepts at the same time, all without creating bottlenecks in the production of the various components.
This undertaking would have required a huge amount of planning, and would only be possible for a large and well-organised team like Mercedes.
Eyebrows raised elsewhere in pit lane
That said, some elements have provoked questions from rival teams, especially Red Bull.
In detail, we refer to the large mid-wing horizontal flow deviators (seen above) which incorporate the anti-intrusion cones on the cockpit sides and also act as supports for the rear-view mirrors.
No other team has adopted a similar interpretation of the 2022 regulations, which aimed to simplify the aerodynamic concept through the elimination of elements that were not integrated into the main volume of the sidepods.
The issues raised by other teams relating to the mid-wings of the W13 concern the lack of adherence to the spirit of the regulations, which do not require the anti-intrusion cones (the lateral safety structures) to necessarily fall within the volume of the sidepods.
This has created a grey area within the rules which Mercedes, whose wing profile also supports the rear-view mirrors, have wisely exploited.
Mercedes confident design is legal, while F1 have their say
However, Mercedes Team Principal Toto Wolff is convinced of the legality of the W13.
"The process is very clear," said Wolff, speaking to select members of the media in Bahrain, including RacingNews365.com.
"When you go in a specific development direction, the team are having the FIA part of scrutinising it.
"You're exchanging data and you're making them part of the process.
"I think the car, we are really proud of what we have achieved in terms of the concept, but now we need to make it go fast."
F1 Managing Director Ross Brawn acknowledged his surprise at the W13's evolution.
"I think there's no doubt the Mercedes concept we didn't anticipate," he told F1 TV.
"It's a very extreme interpretation of the regulation, and I think there's going to be a lot of debate about their interpretation. That's what happens with new regulations."
Will rules be changed to outlaw Mercedes' design?
As the newest W13 appears to conform to the 2022 rules, any mid-season changes to the regulations that outlaw Mercedes' approach will require the sign-off of eight of F1's 10 teams.
At the end of the day, it is true that it is not a 'B' version of the car we saw in Barcelona, and we can't consider it a zero-sidepod concept.
There will definitely be gains that the engineers have seen in their simulations, otherwise they would not have pursued such a development.
Apart from the aforementioned legality of the mid-wing section, it remains to be seen what sort of an effect the new design will have on the performance of the W13.
Let's wait and see if its performance at next week's Bahrain Grand Prix will be as striking as its appearance.
Video: Are Mercedes playing it safe with the W13 reveal?
Mercedes showed off two different versions of the W13 during their 2022 car launch, with some key differences between the digital and physical models.