Analysis: Modest developments on Sauber's C45 hint at heavy Audi 2026 focus

Perhaps the most obvious change for Sauber in 2025 is the increased use of neon green around the front end. Fittingly, for the incoming Nico Hulkenberg, the shade is not too far away from the moniker he shares with a certain verdant superhero - although it's arguably more Kermit the Frog than The Incredible Hulk.

There is a clutch of differences to the Sauber C45, although we've held off reviewing them until the real car had emerged as the veracity of renders can't always be taken for granted. Ultimately, and unsurprisingly, there are familiar notes to the aerodynamic concept as the team is still largely focused on ensuring its evolution into Audi's works team starts on the front foot. Yet, last year's arrival of Mattia Binotto as chief shook the Hinwil operation out of its holding-pattern stupor, leading to a series of late-season developments that have been carried forward.

The front end, for example, is similar to the C44's end-of-season specification; trapezoidal endplates and a pointy nose remain key features at the tip of the new car. That said, the team has iterated on its wavy upper endplate, although strays from the common convention of prioritising a fully inboard-loaded component. Instead, the outer middle portion has the greater camber here, perhaps as a tool to limit any turbulence produced by the tyre.

Sauber switched to a pull-rod front suspension last year; this has continued into the 2025 car, as has a low-mounted rear leg to its upper wishbone which suggests that the team has maintained its efforts to limit any dive properties as the car decelerates.

The biggest visible change to the car lies in its sidepods, which are a development of the geometry that the team ended 2024 with. Owing to its in-season development, Sauber had adopted the overbite sidepod inlet that allows a bit more separation between airflow earmarked for the undercut channels and that to be used over the top. The overwing here also leaves a free tip to be used to generate any required vortices to strengthen the airflow passing over the sidepod.

Like most teams, Sauber has kept its 2025 developments in check to not underpower its 2026 plans

Photo by: Autosport

An interesting minor note is in Sauber's treatment of the mirrors, which reflects well on the team's ingenuity; it has taken a minimalistic approach to the overall shrouding, but has included a little fin on the outboard edge that helps to condition and direct the flow that pours off here. The clutch of small fins that sat behind the mirrors last year are now gone from the equation.

The sidepods also maintain the bulged undercut to mitigate any potential generation of lift, but the top edge now features a divot along the edge which may be a concerted effort to bleed off flow to the lower part of the sidepods. In this instance, you have the flow moving over the top of the sidepods closer to the centreline, and the outer topside flow spilling over and being carried around by the higher-energy flow through the undercut towards the top of the diffuser to improve the consistency of top-surface pressure.

For a team that spent virtually the entirety of 2024 at the rear of the field, Sauber's latest effort does not necessarily appear to be a significant step up to change that fact

Sauber has slimmed down the engine cover slightly, continuing with the flared exits around the Zero Petroleum logo on the car. The slotted shark fin remains in place to free up any small centreline outlets. The rear wing remains in a familiar form to last year, with the upper wing element featuring a small degree of contouring along the trailing edge to trim off drag and downforce from the outermost edges.

For a team that spent virtually the entirety of 2024 at the rear of the field, Sauber's latest effort does not necessarily appear to be a significant step up to change that fact. But, as mentioned, the focus on pulling everything together for the Audi 2026 project is all encompassing; pouring resources into 2025 and potentially hurting the Four Rings' arrival in F1 is not something that the German manufacturer will want to risk. There are refinements for 2025, but this should simply make last year's slowest car slightly less recalcitrant...

It is not easy being green... even with a splash of red

Photo by: Clive Mason/Getty Images