Mercedes needed little time to let its F1 rivals know that it has pulled out all the stops to deliver another pace-setting car in 2016. But, as Giorgio Piola and Matt Somerfield examine, is the car a radical departure or standard evolution?
Front Wing & Nose
It was the nose that grabbed most of the attention, as the car was wheeled out into the pitlane on Thursday morning, with everyone eager to capture the details of the 'S' duct.
However, the front wing also featured some revision too - and the team admitted that making sure it would be strong enough to pass F1’s deflection tests had been tough.
For the front wing connecting pillars were spaced extremely narrowly, and changes had been made to the juncture between the neutral section of the mainplane and the flapped region (above). However, the team is satisfied it is all good to run in its current configuration for Melbourne.
The changes made here are purely aerodynamic with the surface geometry changes resulting in a different collision of the pressure gradients. This changes the shape of the Y250 vortex, in the hope of improving performance downstream.
While we think it is still best to call this an 'S' duct, it doesn't follow the same lineage as the McLaren or Force India setup.
The inlet is placed much further forward than the intended 150mm ahead of the front wheel centre line that they abide by.
Instead it follows a similar design philosophy to the Ferrari F2008 (below). The team is working the front wing neutral section and underside of the nose much harder, but in a very different way to the other teams.
In the case of Mercedes, the pelican underbelly (darker, under section of the nose) is not part of the crash structure and likely follows the single section rule (3.7.8) to allow the forward inlet to deliver airflow to the pipework installed inside the 150mm zone ahead of the bulkhead.
The new nose and wing were also partnered by a new set of turning vanes, very similar in geometry to their predecessors. However, the new solution features six slots in the footplate, which should work the airflow more aggressively.
Between the turning vanes is the 'Bat-Wing', first adopted by Mercedes on the W05, used on the W06 and so it would seem again in 2016.
Whilst the turning vanes can do so much for the airflow moving under and around the nose, the Bat-Wing, which sits astride the ride height sensor, improves flow to the underside of the chassis, splitter and then onto the bargeboards and sidepod undercut.
The bargeboard arrangement run by Mercedes from day two of the first test are, in isolation, similar to a concept we have seen Lotus run in the past.
However, combined with the new strakes that they're mounted upon, it adds a new dimension to what is being done in this area.
The 'bargeboard' not only helps to control the airflow around the sidepod's undercut, it also helps with underfloor performance. This is of particular importance when we consider that a car must create its most downforce in yaw.
The strakes added by Mercedes are placed as such that they will help the floor to perform better over a wider operating window, straightening the flow and retaining the air structures angle of attack.
As is always the case, it is difficult to examine these parts in isolation, instead they must be seen to be helping to improve the global performance of the car.
Sidepod shaping and new fin
The sidepod shape is governed by the components that are housed within, whether it be electronics, air-to-air coolers, radiators, oil coolers, pipework etc. Furthermore, the thermal output of the power unit must be considered, with the internal airflow important to how the car's aerodynamics operate globally.
Mercedes has undoubtedly made changes under the skin, with the surfaces dramatically sculpted, maximizing performance.
The sidepod undercut affords a generous space for the airflow to move around the sidepod, so much so that the team have hung another vane from the sidepods corner with which to define the airflow.
In the upper, outer corner of the sidepod, we can see that the team has taken a huge notch out of the bodywork, exposing the side impact spar, in a similar fashion to how Ferrari did with their updated bodywork in Spain last year (below).
This has led to the horizontal leading edge slat being raised when compared with the W06, which should improve the sidepods operating window.
At the rear of the sidepod, the cooling outlet has been raised, improving how airflow moves around into the coke bottle region, again, improving performance.
The airbox is just as aggressive as the rest of the car, with the large inlet combining both the turbo compressor feed and the additional 'ears' previously used on the W05 and added to the W06, when its demands exceeded what could be achieved with the standard cooling.
This is part of the reason the team has been able to shrink the sidepods, with some of the coolers moved inboard.
The inlet is also slanted backwards, further increasing the frontal area. Meanwhile, the slant promotes how the airflow moves around the air box's undercut too.
Note, the large camera mounting on either side of the airbox cannot be raced. We have seen them used by Mercedes before, with them home to more thermal imaging cameras that look at the front and rear tyres, feeding the team with information on how setup changes affect the tyres performance.
Floor (Tyre Squirt)
The floor has been amended ahead of the rear tyre, with three additional L shaped slots added as the team look to further marginalize the effects of tyre squirt. For the uninitiated, tyre squirt is when airflow is spilt by the rotation and deformation of the rear tyre into the diffuser, causing a loss of performance.
At the rear of the car, Mercedes, like most of the field, has opted for two wastegate exhausts, although it mounted its in the double barrel shotgun configuration, rather than the inverted Mickey Mouse that others seem to have.
This has had a knock on effect to the treatment of the Y150 region, with the team abandoning the winglets it had mounted on either side of the crash structure in 2015.
Extra downforce found elsewhere by a team can often lead to a little more instability. So
it is using a Y150 winglet (Monkey Seat) to add balance.
It is similar to the design it used in 2015 at the higher downforce circuits, albeit with an additional slot, improving efficiency.
It is rare for teams to break with an evolutionary design philosophy during a relatively stable regulation period, but it seems Mercedes is planning on just that.
The threat from the red team in the garage next door appears to have been enough to shake Mercedes into producing a rather different car this season, with the updates run during the first test indicating that it is prepared to converge on others ideas but to think outside of the box too.
With more parts expected to arrive for the second test the W07 stands out as a clear contender to retain both titles in 2016.