Mercedes introduced a plethora of updates for the Chinese GP, some in reaction to Ferrari’s upturn in form and others were simply scheduled updates.
The team have done a lot of work at the rear of the car, including the introduction of a new rear-wing top flap, aimed at reducing drag.
The design is very similar to the one employed by the team at Spa-Francorchamps in 2014, featuring a cut out at the flaps outer edge (see top image).
The curvature of the flap results in a change to how the pressure gradient builds across the flap, whilst the vortex that is usually shed from the tip juncture will also change shape.
If carefully balanced, the loss in downforce will be minimal compared to the amount of drag that can be reduced, thus creating a higher top speed on the straights without compromising cornering speeds.
Another change to the rear for China was a revision to their cooling package (see image below). The team have shrunk the lower outlet, which previously had a flat upper section (see inset image below) to better shape the airflow in the region, further reducing drag.
This could have an impact on cooling efficiency and with the hot Bahrain race coming up, it’s possible they could return to what they ran in Malaysia to avoid overheating, before returning to the China-spec for the European season.