Sauber’s Glowing Wheels Are The Biggest Controversy of F1 Testing So Far

Formula 1 testing has now begun in earnest, with fans and pundits alike pouring over footage for any little quirk or secret they can find. Surprising everyone, it’s Sauber that has been making waves with its new glowing wheels. Based on our analysis though, it’s not quite what it appears at first glance.

Video of the F1 testing broadcast was shared on Twitter, and revealed something striking. During a Sauber pit stop, a ring on the wheels could be seen glowing purple and then green as the mechanic affixed the wheel.

The striking visuals led to rampant speculation that Sauber had integrated LED lights into their wheel covers. However, the reality may be rather simpler than that.

#Sauber has LED lights on the wheel covers so mechanics know when the wheel is properly attached ???????? #F1 #F1Testing pic.twitter.com/cilncXvZ0Q

— Moni Maldonado (@Moni_Maldonado) February 26, 2025

Careful viewing of the footage reveals that purple LED lights are mounted on the wheel gun itself. It appears that rather than mounting LEDs on the wheel cover, Sauber has instead found a way to style the wheel covers to reflect the light from the wheel gun back towards the mechanics so they can see it more easily. The wheel gun itself starts out glowing purple, and turns green when the correct torque has been applied to the wheel nut. The wheel cover just shines that light back in a ring so it’s easier to see.

Using a reflective coating on the wheel covers makes a lot more sense than putting LEDs in the wheels themselves. Going that route would involve adding electronics and a power source to the wheels themselves, which would be relatively complex and heavy versus a reflective coating or sticker.

Furthermore, the wheel covers are spec parts, which teams are not allowed to unduly modify beyond simple cosmetics. The FIA would be unlikely to allow the installation of LEDs without spending six months trialing the solution first. Indeed, the series contemplated the idea for a while but abandoned it in 2023.

Indeed, some have speculated on Reddit that this wasn’t even intentional. The wheel covers themselves are finely-manufactured carbon fiber parts with a glossy surface finish. It may just be a quirk of their design that they appear to be illuminated in this case. The F1 broadcast doesn’t show us a close enough shot of the wheels for us to determine if there’s some kind of sticker or other coating that’s helping the wheel really shine that light out, but it does appear as if there’s some fiber optic or light pipe effect going on nonetheless. The Autopian has contacted Sauber regarding the matter.

Sauber are using LED lights to help with wheel changes this season ???? pic.twitter.com/zCYpmtNSLL

— Autosport (@autosport) February 26, 2025

Note the purple light reflected on the mechanic’s leg.

Indeed, the lights themselves aren’t a new development. In the video above from last year’s Singapore GP, for example  LEDs were readily visible in Sauber’s wheel guns. What appears to be new is the wheel cover that so elegantly shines this light back at the pit crew.

Naturally, glowing wheels are a plenty exciting sight all on their own. It’s only magnified by the context in this case. Sauber spent much of 2024 struggling with its pit stops, because somehow a bunch of F1 engineers and millions of dollars couldn’t figure out how to make a reliable set of wheel nuts. Valtteri Bottas suffered a particularly embarrassing 52-second stop at the Bahrain Grand Prix, and the teams woes continued for multiple races afterwards.

Bottas summoned to the stewards for pit lane incident – notice the loose wheel nut falling into fast lane. #AustralianGP pic.twitter.com/dFHOjMcAkP

— Maxx | F1newsletter.com (@F1_Newsletter) March 24, 2024

Sauber didn’t have many good pit stops in 2024. 

F1 testing has otherwise been uncontroversial on day one. As reported by Autosport, Liam Lawson spun his new Red Bull, while Kimi Antonelli impressed on his debut with Mercedes. Lando Norris ended the day quickest, but the jury is still out on which team will have the fastest car come the first round.

Will the new glowing wheels make a difference for Sauber this year? It’s hard to say. If they are intentional, and if they make it easier for the mechanics to see what’s going on, they certainly can’t hurt. If Sauber can combine this with a reliable set of wheel nuts and the right training drills, it should certainly help get their pit stops down to a more competitive time. The proof will be readily available when the Melbourne Grand Prix rolls around in two weeks’ time.

Image credits: F1 testing broadcast via Twitter screenshot
Top graphic image: Sauber