McLaren have followed their own strategy on the DRS rear wing this season. In contrast to other teams McLaren have designed their wing for the best Non-DRS Performance, thus when deployed the DRs provides a more modest boost in speed. This Strategy appears to have been reviewed as their new rear wing tested at Silverstone shows.
Already being one of the fastest cars in a straight-line, McLaren perhaps haven’t needed to exploit DRs as much as other teams. Their current wing sports a large flap which due to its geometry flattens less when DTS is deployed. See DRS Geometry. But we have seen that McLaren can deploy their DRS less on Q-laps and despite their KERS and speed, sometimes struggle to pass other cars. SO their new wing exploits more conventional geometry with a shorter chord flap that flattens out more completed to maximise the drag reduction system.
Along with the shorter flap other aspects of the wings design have changed, the slots on the endplate have been made even more shapely and the endplate merged into the flap. These slots have been a feature on F1 rear wings for nearly ten years. They aim to take some of the high pressure air above the wing and direct it out through the endplate at the wing tip. This reduces the pressure differences that create the vortices at the wing tip, these vortices often seen in damps condition create a large amount of drag, reducing them further aids top speed.
Although the slots are so curved it’s hard to detect, but the sections between these slots on upper part of the endplate are directly joined to the flap, thus the flap is remotely mounted, the loads pass through these three narrow section of endplate. This must be quite a structural feat. This design harks back to McLaren’s 2008-209 wings (see below) which mimicked the Renault practice of merging the endplate into the flap. Again the aim of this design was to manage the pressure differences at the wing tip for reduced drag.