Uncovered: McLaren’s subtle change that yielded big performance gains

Matthew Somerfield 27 Jul 2025 11:38 AM

McLaren have introduced another option for their rear wing in Belgium, which takes the main specification used in Saudi Arabia, Miami and Silverstone already and breathes new life into it.

At a circuit that demands a compromise between low drag for the first and second sectors, whilst being mindful of the downforce requirements and challenges posed by the twistier second sector, rear wing choice is pivotal. Especially given the impact that changeable weather conditions can have on the choices made.

New and old combine

The main rear wing assembly of the McLaren, including the mainplane and upper flap remain untouched by the update, with gains made from a redesign of the tip section.

It follows a similar design path as the other solutions in the pool, with less curvature present on the leading edge and a bolder slot gap separator bracket sat astride the endplates rolled section, ahead of the cutout.

The aim of these changes will result in the main vortex structure that forms here being altered, improving the overall efficiency of the wing.

The team have also continued to apply the same tactic as we’ve seen from them on numerous occasions the last few seasons, where we see them introduce a new solution, test it at that Grand Prix but shelve it for use at a future event.

This time it’s the floor that was tested on Friday at Silverstone, before the cars were returned to their previous specification. The data that was captured was scrutinised ahead of the Belgian Grand Prix, alongside the feedback given by the drivers in order to ascertain it was adding the performance expected of it.

In terms of the design it’s not a total overhaul, rather a subtle reimagining of what came before it, as the designers look to extract a little more performance, without upsetting the apple cart.

The new edge wing (right) has a number of features that have been adjusted to improve flow stability and seemingly increase stiffness too.

The swept section at the front of the edge wing has been increased in length, which has required the camber of the surface to be altered, whilst the number of vanes that are fully exposed has increased from two, to four.

F1 2025: The season’s winners and losers

? The results of the F1 2025 championship

? The updated Drivers’ and Constructors’ Championship standings

Previously those two rearward vanes sat beneath the tideline, still having an influence on the airflow but likely not with as much authority.

The shape of the floor’s edge and the tail section of the edge wing have also been adjusted, as there’s further changes made to the geometry of the tunnel on the underside of the floor, resulting in the number of metal support brackets being used housed between them being increased.

There’s now four support brackets in this region, rather than two, as the team are obviously being more attentive to the loads being generated and how flutter might be created should the edge wing not be secured effectively.

Just as we find with all of the teams in the aftermath of the revised front wing load and deflection tests introduced at the Spanish Grand Prix, there’s some tidy-up work being done in combination with the continued search for more performance.

This isn’t only isolated to the front wing either, as the surfaces downstream have been affected and need to be optimized to suit the new flow conditions, with the bulk of the work done by teams since about recovering some of their perceived losses.

Whilst we’re sort of on the topic of the front wing, it’d be remiss not to show this great shot of the ‘mermaid tails’ on the MCL39, as it’s from an angle we’re not usually presented and goes to show how the winglets mounted on the flap tips combine to make a cascade.

McLaren