The major update Mercedes finally unleashed

With just four rounds left of the 2019 Formula 1 season, the attention of designers, engineers and technicians has very much shifted towards preparing for 2020. But with a predominantly stagnant ruleset, development parts for next year can be given a good run-out in these final rounds to check windtunnel and simulation correlation.

But not everybody has given up on 2019 just yet. While there were certainly development parts spotted in the truncated Japanese Grand Prix practice sessions, there was also a healthy supply of upgrades for the rest of this season too, especially with constructors' championship placings - and the prize money associated with them - still to play for.

Suzuka itself is a circuit that requires plenty of balance, with good front turn-in properties and a stable rear end - and so any circuit-specific upgrades must be able to give a driver plenty of confidence on one of F1's most technical tracks.

Mercedes turns the tide

In reality, Mercedes never looked threatened by Ferrari when it came to the constructors' championship, but it has been resigned to playing second fiddle in recent rounds as Sebastian Vettel and Charles Leclerc shared the headlines.

Ferrari's recent form had also prolonged the wait for the 2019 crown, and Mercedes needed to arrest its deficit at Suzuka to sew up the title for another year. Crucially, the team hadn't planned many upgrades after the summer break, but that was to change in Japan as it brought another new turning-vane package to provide a long-awaited aerodynamic boost.

It's an area where Mercedes has placed a lot of attention this season, and the latest specification looks wildly different from the arrangement with which the team began the year. Now, the design features six horizontal elements that twist to a greater degree towards the rear, feeding into a newly reprofiled sidepod-mounted turning vane.

This part has now been split into two; before, it attached to the winglet passing over the top of the sidepod, but Mercedes has chosen to exploit the vortices produced by the exposed edges and improve the suction effect to the rear of the car.

The horizontal elements also allow for more integration with the bargeboard package, collecting the airflow channelled outwards and turning it around the undercut of the sidepods.

Compare that to what Mercedes had at the start of the season, which now looks incredibly simple by comparison. In context of how the team has developed its bargeboard package, redirecting airflow to areas where it's more efficient means that the aero parts behind have to be redefined to reflect that. The increasing prevalence of bargeboard furniture means that, if Mercedes didn't develop the parts further back, the aerodynamic package would not work as cohesively.

Two small deflectors were also fitted to the front-wing endplate, with the aim of nudging the airflow downwards and outwards with greater strength.

Although race winner Valtteri Bottas suggested the new parts weren't quite enough to overhaul the team's qualifying deficit to Ferrari, he declared the car "a lot better than before" - and with the confidence to control the race, Mercedes produced its most complete weekend display since Silverstone - and with it, a well-deserved sixth constructors' title in a row.

Williams's wing controversy

After the Japanese Grand Prix, Williams driver Robert Kubica launched a tirade on Polish TV levelled at his team, which he accused of reneging on an agreement for him to run the development-spec front wing that he and George Russell had got some mileage with in free practice.

Both drivers ran with it back-to-back in FP1; Kubica put it on first, as the team simultaneously had Russell chalking up the miles with the old-spec wing. The two swapped for the second half of the session, and the team then continued its exploration of the new wing on Kubica's car for FP2.

Reviews were mixed to a degree; although both drivers knew it had potential, Russell was more reserved than Kubica and suggested it was still a work in progress.

The original wing had only undergone minuscule changes throughout the year, and this development spec (below) built on the 2019 trend of using the outboard section of the wing elements to promote a stronger outwash effect by mounting them lower down. This sweeps up towards the inboard portion of the wing, which develops the majority of the downforce output.

While it presented a more sophisticated concept, it appeared that, from the outset, it wasn't expected to be raced with; indeed, word from the team throughout had been that it was an experiment, and something to base their 2020 designs upon. Kubica's subsequent outburst, in context, seems to refute that idea.

The most salient point is that Williams only had one construction of the new wing. One steaming hot take from one of Kubica's most ardent supporters, cementing social media's reputation as a hive of overreaction and toxicity, queried why Williams had only brought one - preceding a slew of insults that questioned the team's integrity.

Regardless of the troubles that Williams had at the start of the year, during which manufacturing processes required a lengthy inquest, the team seems to have got over that and has been giving its FW42 the development it needs to close the gap to the rest.

In reality, a team only needs one wing to conduct development work back-to-back. By putting both drivers on track at the same time, in the same conditions, the aerodynamic balance and outputs can be compared against each other. The team did that in both practice sessions, and the wing returned to the pits in one piece - absolutely crucial for Williams, which was already under fire from sponsor PKN Orlen for retiring Kubica over spare-parts concerns at Sochi.

After Kubica crashed in qualifying, putting him back on the old wing - which the team had three of at Suzuka - seemed like the right call.

Although Kubica took the blame, he still shirked some of the responsibility and suggested that some of the changes made between practice and qualifying had contributed to him putting a wheel off the track and finding the tyre wall on the exit of the final corner. It seemed that he felt he was entitled to the new wing, suggesting that Russell didn't really fancy it.

As a result, Williams has been placed in a bit of a lose-lose-lose situation. By ultimately running both drivers in an equal specification, Kubica has encouraged the ire of his sponsors and supporters. Had the team put the wing on Russell's car, it would prompt further complaints of unequal treatment, and had Kubica run with it then there's a good chance he still would have binned it on the exit of the chicane.

It seems like a once-harmonious relationship has long since soured, and if PKN Orlen's money wasn't helping to financing the team, Williams and Kubica would have parted company some time ago.

Renault soars with new wings amid braking protest

Unlike Williams, Renault didn't have to endure the fury of a driver scorned over a front wing - both drivers had its new specification available and ready to race with at Suzuka.

Rather than buying into the latest 2019 wing trends, Renault has gone its own way with front wing development - although it's pulled a little bit of inspiration from Red Bull in how it operates the inboard part of the wing.

By creating a small cut on the third element of the front wing, aerodynamicists can change the way an all-important vortex forms at the tips, which is fired behind the wheel to drive the turbulent wake away from the front of the floor. This stops little pockets of turbulence disrupting the level of downforce produced at the rear of the car.

By pulling these wing tips close together, the vortex becomes tighter and stronger. The previous solution had been to bring the tip of the final two elements all the way down to the third element's tip to do that.

Instead, as the rules permit five elements within a cross-section of the wing, teams have been able to shorten the top element and create a slot in the third to bring those vortex-forming tips together. Renault has also increased the curvature of the mainplane at the point where it meets the neutral section to start the rotation of air a little earlier.

The team, for its efforts, claimed a double-points finish - but in the aftermath of the race, was officially slapped with a protest by Racing Point, which alleged that Renault was running with a seemingly automatic brake bias system.

Although the details are currently unknown, the regulations only permit a driver-operated manual system to change the bias for each corner. If Renault has been slyly running with a system that allows the car to automatically set up different ratios for each corner, then there could be some very serious consequences.