A flurry of activity over the first four days of testing means we have seen most of the 2016 machinery, with just Sauber yet to unveil its car. Giorgio Piola and Matt Somerfield analyse the prevailing trends.
Stability in the regulations inevitably leads to a convergence of several key concepts and are usually areas of the car that must be fixed within a team's overall philosophy.
There are a few design features that seem to be cropping up on multiple cars, as everyone looks for bolt on performance whilst in the early design phase, before searching for refinement.
Of course, all of these are interpreted differently by each team as they look to improve upon what has gone before.
When the FIA reduced the width of the front wing in 2014 from 1800mm to 1650mm, it was done knowing that it would have an impact on how airflow would move around the car.
Whilst it isn't a huge deal in terms of the downforce generated by the wing itself, it is in terms of how the wing is used to shape the wake shed by the front wheel and tyre.
In order to marginalise this problem, each team will use different methods [see the Williams FW35 above to illustrate this], with both wheel design and the way in which airflow is ejected by the brake ducting important to how the air flows around the wheel and tyre.
On top of this, the teams have been playing around with the idea of a blown axle now for years, with Ferrari, McLaren and Red Bull [below] using them last year, albeit with the latter only utilising it on higher downforce tracks due to how it reshapes the airflow downstream, either improving or destroying floor and diffuser performance.
In 2016, we've seen Toro Rosso and Haas join those ranks as they too go in search of aerodynamic gains.
Airflow collected by the front brake duct is sent off in various directions, be it to cool the caliper, brake discs or, in this case, feed the hollowed out axle.
Using the image above to illustrate how the blown axle works, yellow is the wake shed by the tyre and blue is the airflow blown out of the axle, which helps shape the tyre wake.
Remember though - this is just for illustrative purposes, with each design different based on a huge amount of factors.
Having pioneered the conjoined wishbone arrangement in 2014, Mercedes has continued to develop its offering.
The idea is that the suspension elements, which ordinarily create turbulence, are shaped more carefully so that the airflow has less work to go through.
Meanwhile, McLaren has bucked that trend, choosing to move the rear arm of the upper wishbone closer to the lower rear arm [marked in yellow], which should create a bulk flow structure, rather than individual ones.
Like the blown axle, the 'S' duct is nothing new [see the Sauber C31 illustration above] and how it is used changes based on the prevailing regulations.
However, with the nose regulations stable this year, we are seeing more refined concepts being used. Red Bull, Force India and McLaren all ran 'S' ducts during 2015, with the latter using a dual pipework and outlet installation [below].
Force India and McLaren have continued to use them on their 2016 challengers and at the moment they've been joined by Toro Rosso and Mercedes, although it is possible this list could grow to include Ferrari and Haas, based on key indicators shown in early trim.
The oddity at the moment is Red Bull, as it has dropped their 'S' duct at this early stage, which is strange considering it's the team that, perhaps, pushed its development the most in recent years.
Toro Rosso's solution is a very neat package that is all housed within the nose box, rather than having separate 'S' duct pipework mounted in front of the bulkhead, like we have seen before.
This is quite novel as it changes the point at which the airflow has an effect on the air passing over the nose, for which it is intended to help.
Two NACA-inspired ducts are placed on either side of the nose and collate airflow that is sent through the internal pipework and ejected out of the raised letterbox-style outlet at the rear of the nose section.
The idea is to use the Coanda effect - drawing nearby airflow that is detaching from the nose surface, by virtue of the steep inclination, and bringing it back onto the surface, improving performance.
'Tyre Squirt' slots
This is an area that has been under heavy development for several seasons [see image above, from last season], however, from time to time, trends emerge. One such trend is all of the teams adding more slots than ever, extending quite far forward on the floors surface.
The solutions used by Mercedes and Haas [above] are similar to the design employed by Toro Rosso in 2015 [below], with several L-shaped slots raising the floor in order to mimic a hole.
A fully enclosed hole in the floor, whilst more effective, was officially ruled out in Monaco, back in 2012, when Red Bull was pushing their interpretation of the regulations.
Since that moment, the teams have been adding almost imperceptible slots to the floors edge, by virtue of which it is then no longer a fully enclosed hole.
These slots, and the holes that preceded them, help to combat a common foe – "Tyre Squirt", something that has been more critical since the rules stopped the teams from sealing the diffuser with exhaust gasses.
Ordinarily, airflow is "squirted" laterally into the diffuser's path as the tyre rotates and is exacerbated as the tyre deforms under cornering load.
The idea of the slots, along with other devices on the floor, like the vertical strakes, is to minimise this issue, by creating vortices that help re-align the airflow before it even makes it into the diffuser.
Rear wing mounting pylon
While Toro Rosso has followed several design paths forged by others this season, it is one of the squad's designs that is now being proliferated up and down the grid.
As shown above, during 2015 the team used a rear wing mounting pylon that intersected with the exhaust, using, as is so common, a grey area within the regulations.
In doing so, it was able to trim a little weight, as it was no longer using a heavier inverted Y-Lon. The switch also has some aerodynamic payoffs, too. Firstly, this removed the circular Y-Lon from the equation, giving airflow exiting the engine cover one less obstacle to deal with.
Secondly, the mere fact that the exhaust has the pylon running through it means the exhaust plume is affected.
Although the engine manufacturers have gone to great lengths to design their turbo exhaust exit in such a way that is beneficial for performance, the plume generated is still likely to be more erratic than is desirable.
It can, therefore, be inferred that the pylon will act as a flow stabiliser, straightening the plume, perhaps not only improving things aerodynamically but indirectly improving turbo performance.
Even though it's using the 2015 Ferrari powerunit, Toro Rosso has retained its intersecting rear wing mounting pylon, whilst Ferrari [above], Haas [below] and McLaren have all copied the solution too.