F1’s wheel cover tests to resume next year after teams seek delay

The FIA has been evaluating ways of adding covers to wheels in rainy conditions to help minimise spray being thrown up, which can severely restrict visibility.

Trials of an early design tested at Silverstone earlier this year did not deliver the results hoped for, with the conclusion being that the first iteration concept failed to cover enough of the wheel. 

A second, bigger design has been in development since then and was originally hoped to be tested on cars last month. 

However, amid the logistical challenge of the intense end of the season, allied to cost implications, teams that had been offering to help out felt that it would be better to hold fire and wait until next May to plan the next run. 

FIA single-seater director Nikolas Tombazis said the governing body was happy to listen to the teams over how best to approach the next stage. 

“Obviously for these tests, we get support from the teams who do the work, we don't have cars ourselves,” he said. 

“The work that had been planned was going to happen around about early November, but parts availability and production capacity of the teams involved meant they would have had to get everything supplied externally - and that would have been very expensive.

“So, they asked whether they could delay the test until the spring in order to cut the cost out of it. We thought that was sensible.  

“From a technical point of view would have preferred to have done it already, of course, if it wasn't too expensive.” 

Diffuser question

Tombazis said the FIA understands that it will be a nigh-on impossible target to produce covers that eliminate spray totally, but it felt significant improvements can be found. 

However, critical to the situation was gaining a better understanding of just how much spray is thrown up by the diffuser of the current ground effect cars.

“The [original] covers were too small, and they didn't really cover enough of the wheels,” he said. “We felt that they therefore didn't really answer the question of whether that's a cure or not.  

“What we still have a doubt about is what proportion is due to the overall diffuser and sucking the water from the track, which is something clearly this thing won't fix, and how much of it is because of the wheels.

“We know both factors are quite significant, and clearly we're not here aiming to solve everything.  

Photo by: Red Bull Content Pool

Max Verstappen, Red Bull Racing RB19

“We know there will still be visibility issues, but we have got to see what percentage we can cure by a very complete cover of the wheels. If we see that's actually a tangible step forward, then we'll optimise that. 

“So, what we're testing in May isn't the final solution. It's, sort of, information gathering to see if that is actually the right path.  

“Alternatively, if the test doesn't go well, in spring, we may abandon that course and then have to rethink about what to do.”

If the next test is successful and offers a potential wet weather solution, then there could still be time to get it on the cars for the 2025 season. 

However, if more work is needed then things would likely wait until 2026. 

The issue of the diffuser is important because if it is found that more spray is being thrown up from underneath the car, then that may prove more problematic to solve. 

Asked by Autosport about potential ways to prevent spray being thrown up by the diffuser, Tombazis said: “It would be too complicated to do that on the set of regulations with cars that you have in one configuration when it's dry and have to somehow make a modification when it's wet.  

Photo by: Erik Junius

Max Verstappen, Red Bull Racing RB19

“If we conclude that the main factor is the diffuser, then I think that the direction the 2026 regulations are going, that will make a step improvement. But secondly, then we would be able to focus some of the work there and see what more we can do.” 

Tombazis also said introducing something like an air curtain, which could direct spray back towards the ground, was not realistic. 

“It's a bit difficult to put things there and not to lose downforce,” he said. “One of the challenges of these wheel covers has been not to lose too much downforce. So, it's a bit of a trade-off. 

“That [idea] has been proposed but if you put something in that area, you would lose downforce. And if you lose something like half the downforce of the car, then drivers are suddenly faced with a car that has very little grip. So, are you safer or not?”