Ferrari has been assessing different options for its rear brake ducts in Brazil, with Raikkonen testing a solution that both drivers latterly adopted during FP2.
The change has a two-fold effect, changing both the aerodynamic characteristics and also how much air is drawn into the inlet for cooling the rear brakes.
The vertical fence that sits alongside the tyre's sidewall has differing heights, which also isolates the horizontal footplate vane that sits at the base of the brake duct on the shorter version (above).
These changes, in combination with the change to the floor's vertical strake (below) should help to improve how air moves around the rear tyre and improve their relationship with the diffuser too.
Ferrari has also made a small change at the rear of the SF16-H, amending the shape of the strake mounted on the floor, just ahead and to the side of the rear tyre.
It may seem like a small detail change but the ramifications can be quite significant, as this area of the floor is proliferated with airflow conditioning elements that are charged with changing how the airflow spills off the rear tyre.
If left unmanaged the airflow that spills off the tyre becomes destructive to the diffuser, which is a term we know as 'tyre squirt'.
The rotation and deformation of the tyre under load squirts airflow laterally into the diffuser, changing the shape of the airflow passing through it.
The diffuser is designed in such a way that this is acceptable up until a point but, inconsistencies in the dynamic behaviour of the car will lead to instability and reduce performance.
The various slots and strakes used by the teams will manage the issue very differently and often change things when a geometric variant shows promise in CFD & Wind Tunnel testing.
In the case of Ferrari this has led to the straightening of their strake, with just a very small curvature left on the upper leading edge. This change in geometry will have an impact on the vortex that is shed from the strake, with the previously curved element (inset) producing a very different effect.