Renault has used limited time in the first free practice in China to test the new configuration of the rear wing that is different from the one used in Australia.
The 2017 rear wings are wider and lower and thus more exposed to turbulence rotating the rear wheels while the lower portion of the endplate is narrower than the upper to allow the teams to use this space for the rear brake cooling and vertically stacked fins which produce downforce directly on the rear wheels.
Also, due to twice larger diffuser (and greater width of the rear wing) teams can use the lower angle of attack of the rear wing to produce the desired level of downforce.
The new rear wing on Renault R.S.17 has straight middle leading edge of the mainplane but its edges are bent down close to the wing endplates.
The upper element has a flat lower edge and on the wing from Australia, and the top edge is cut out in the middle in the shape of the letter ‘V’ on both wings specifications.
Wing from Australia has a curved bottom element which gently rises towards the center with a very similar flap as wing tested in China.
Both wings have Gurney tab on the upper edge of the flap (above ‘Renault’) which increases downforce. Teams add these tabs manualy to fine adjust downforce requirements that they want to achieve on a particular track.
Due to very limited number of laps in first practice, there is a possibility that Renault will test both rear wings on Saturday to determine which configuration is more appropriate for a fast track in Shanghai.