A first trial of an idea at Silverstone in July did not yield the results hoped for, with the wheel-fairings used only reducing the spray thrown up by a small amount.
F1 chiefs know that a much bigger step is required if they are to limit spray enough to help cars race more in rainy conditions.
The FIA’s single seater director Nikolas Tombazis has explained that, following analysis of what happened at Silverstone, the next test will be with a much different design.
“What was done at Silverstone, with the help of Mercedes who created parts and McLaren [who ran a car to get feedback on spray] was perhaps too optimistic an experiment,” Tombazis told Motorsport.com
“The spray guards covered too little of the wheel. I was quite sceptical and imagined that we wouldn't see important results.
“In the next tests we will carry out, we will test complete coverage of the wheel, going even beyond what would be needed to understand what the threshold is at which the spray forms. Then we will decide which path to take.”
Tombazis has explained just how complicated finding a solution is, with the excessive spray thrown up by F1 cars being triggered by different factors.
“The first is from the water that is extracted from the tyres and shot upwards,” he said. “A second effect derives from the accumulation of water between the wheel and the asphalt in the tyre squirt area (between the wheel and floor edge), which is sucked into the diffuser.
“The third effect is given by the water that stagnates in the cracks in the ground and, under the pressure of the diffuser, is sucked up and expelled.”
He added: “We believe that the spray coming from the wheels corresponds to approximately 40% of the total.
“If we were able to limit this phenomenon, it is clear that the drivers would not have complete visibility, but there would be a significant improvement.”
Tombazis says the FIA has been looking at tools used by the road car industry to simulate wet weather conditions when it comes to ensuring safety.
“We have done some simulations and there are tools that are often used in the production car industry (for example checking visibility for rear view mirrors), but these tools must be calibrated well to have a good correlation.
“The car manufacturers carry out very extensive calibration and, as they do not have testing restrictions and do not have to deal with an FIA which imposes constraints, they can act freely.
“We do not have the possibility to carry out frequent tests, so with limited activities it is not easy to find the right calibrations.”
One of the issues at play with a bigger wheel covering is aerodynamics, as it will have a much bigger impact on airflow than the original test versions.
Tombazis says the FIA is mindful about the impact any device has on this front, but says that ultimately all teams would lose the same amount.
“The [downforce] deterioration can vary greatly,” he said. “In some configurations we tried it was almost zero, while in the most extreme solutions we tested in a tunnel we saw a loss of up to 80 points, which can be worth two or three seconds in lap time.
“But honestly, we don't really care about the performance threshold, although the teams are definitely watching it. In the Silverstone test, the solution tested had the lowest possible aerodynamic impact."
F1 CEO Stefano Domenicali suggested recently that one other idea being looked at to reduce spray was in relation to limiting the amount of water thrown up by the diffuser.
Some cover could be possible, but Tombazis has ruled out interfering with specific design aspects in the tyre squirt area.
“It would take a lot of work from the teams,” he said. “Ideally, we would like to intervene with a solution that is put on and taken off only when there is a wet monsoon, which is perhaps once or twice a year.
“We prefer not to have to touch the machines. Other ideas may possibly be developed for the 2026 regulations.”
