Mercedes started the season with a W15 that proved a tricky beast for both Lewis Hamilton and George Russell.

With the team having no immediate answer about how best to get its car to perform in both high and low-speed corners, much of the early season effort was in getting to the bottom of the issues at stake.

But as it finally unlocked what it needed to do, its factory was moved on to a war footing to deliver update packages that have helped transform its performance envelope and resulted in its first non-sprint podium of the season in Canada.

While there has been much focus on the new front wing that first made an appearance in Monaco, the start of how Mercedes turned things around actually goes back to a few races before.

In fact, aside from a small alteration to the halo fairing and the aerodynamic furniture attached that arrived in China, the first big batch of new parts arrived at the Miami Grand Prix.

The Miami developments

This update package for Miami included some track-specific modifications to aid the drivers and engineers in finding a more appropriate set-up for the challenges posed.

There was also a trimmed front wing, a modification to the angle of the front track rod and a larger louvred panel for cooling on the side of the engine cover.

Mercedes W15 floors comparison, Miami GP

Photo by: Giorgio Piola

More importantly, though, the floor and edge wing had been fettled as part of a longer-term plan to improve the W15’s performance and ability to deal with fluctuating ride heights.

At this stage, we were unable to appreciate the scope of the changes made to the underfloor, as it was hidden away out of sight.

But, given there was visible change on the upper surfaces, there was undoubtedly a considerable amount of work that had been undertaken to improve the geometries beneath.

Allied to this were the changes to the edge wing, which saw the number of strakes housed within the upturned section at the front of the assembly increased from two to five, while their size and geometries were also altered to match the increase in camber the element had received.

These dimensional alterations also resulted in changes to the position, size and shape of the bracketry holding the edge wing to the floor, to account for the change in loads, while the tail section of the surface was also minimally adjusted too.

Imola’s new parts exploited an old idea

Mercedes W15 rear wing Imola comparison

Photo by: Giorgio Piola

The second stage of updates came just a race later, at Imola, with the team once again fulfilling the circuit characteristic objectives within its race-by-race update programme, while also delivering another set of new parts for the floor.

Interestingly, Mercedes introduced a new rear wing at Imola that saw the Brackley-based outfit circle back on itself in terms of development.

After all, Mercedes had initially followed a branch in the development tree seen on the Aston Martin in Monaco, last season, with its 2023 W14 sporting a similar outboard semi-detached tip section layout.

However, the W15 first appeared with a solution that had formed on the other side of the tree, with Alpine first sporting the more well-known semi-detached variant, whereby the lower portion of the surface left the tip exposed.

Mercedes’ Imola version could be considered a new idea in its own right though, as it really takes inspiration from the development we’ve seen from both of the solutions so far.

Most of the teams following Alpine’s example have started to stretch the tip section down over the mainplane, invoking a different level of performance from the interaction of the surfaces around it, such as the mainplane, the rear endplate cutout and the tip section itself, which have also been optimised to suit.

Combining this with the outboard mounting position seen in the Aston Martin lineage of designs, of which Mercedes was one itself, has perhaps given the team more leverage with which to push the geometries of the aforementioned surfaces that work together in this region, leading to an upturn in performance all-round.

It’s clear that this generation of wing is now part of the team’s design DNA going forward too, as Mercedes followed up its arrival at Imola with a higher downforce variant in Monaco a week later.

Mercedes F1 W15 rear detail

Photo by: Giorgio Piola

Mercedes also introduced a new bi-plane beam wing arrangement into its arsenal in Imola, in order that it could find the right efficiency balance between downforce and drag.

The second part of its three-pronged floor update, which was introduced at Imola, concentrated on the floor fences, with their alignment and shape slightly altered to take advantage of the floor volume alterations made at the previous round.

The majority of the alterations were made to the above tide fence (blue arrow, below), albeit the section that was stitched into the pre-existing fence is out of shot.

The new front wing and floor for Monaco

Mercedes W15 floor

Photo by: Uncredited

The update introduced at Monaco was more focused on the floor’s leading edge, as the team followed a development we’ve seen from the likes of Red Bull in the past, whereby it uses a blister on the side of the chassis to pack out the region and alter the lateral position of where the floor begins.

Obviously, this has an impact above the floor’s tide line and beneath, with the airflow’s passage into the sidepod undercut region and the tunnel interface below, both affected.

These alterations not only aligned with the modifications made to the floor in the previous two rounds, but they were also amplified by the introduction of an entirely new front wing layout that arrived in Monaco too.

The team only had one wring ready for Monaco, with Russell granted access to it for that event and then both drivers had it at their disposal in Canada.

Mercedes W15 front wing Monaco GP comparison 059-24-MERCEDES-FRONT-WING-MONACO-COMPARISON

Photo by: Giorgio Piola

The new front wing has a completely different layout when compared with the outgoing design, with the most noticeable difference being the abandonment of the very slender upper flap at the inboard end of the wing.

This decision is further crystallised by a switch to a narrower inboard section, while the moveable section of the two upper flaps has been increased in width.

This obviously shifts the performance envelope of the wing at a given flap angle and also results in the flaps being redesigned as a consequence.

Additionally, the flaps’ change in span-wise distribution has led to alterations to the shape of the nose and to the curved central portion of the wing (red line), which also requires the outboard section of the wing to be rebalanced.

The upwardly curved and arc-shaped leading edge mainplane (yellow highlight) has also been rescinded, as the endplate and the flap juncture have also been re-imagined.

Mercedes W15 front wing endplate juncture comparison

Photo by: Giorgio Piola

The team now has three of the four elements with a semi-detached layout in the juncture, as the mainplane is much shallower than before.

This gives more priority to the second element, while the two rearward elements have been adjusted to work in conjunction with it to help generate the desired outwash effect.

The flap tips and juncture are further assisted in this endeavour by the inboard-mounted hook winglet (red arrow), which is similar in approach to the one used by Haas this season.

While there were no further updates to the front wing or floor in Canada, the team still looked to unlock aerodynamic enhancements, with alterations made to the front suspension fairings that act as one of the intermediaries between those two regions.

This is far from the end of the trail for Mercedes either, as it is bullish about its eventual return to the front of the pack, with technical director James Allison suggesting that the team is going to continue to deliver updates for the W15 over the next few races: «Our challenge is just to keep those upgrades arriving at a pace that the others cannot keep up with.

«In doing that, just bullying our car to the front by virtue of the effort made by everybody here over the coming weeks and months to get the car so that it can have its Montreal weekend or better at any track that we face in the future.»