Tire covers have been part of Formula 1 since the mid-1980s, but in 2024 they will be a thing of the past after several failed attempts to ban them.
The idea of banning tire covers has been bouncing around in F1 for years. The intention was for this to happen as part of the switch to 18-inch rims which came this year, only for it to be postponed to 2024. Before that there was also the intention to get rid of it by 2015 for cost reasons, which was discontinued for security reasons.
There’s still time to drop the 2024 ban, but there’s no sign of that happening. While Pirelli has yet to begin development work on the 2024 rubber in earnest, there has already been slight progress in this direction with the tire cover temperature being reduced to 70°C from the maximums of 100°C (before) and 80°C last year. (back).
This was at Pirelli’s suggestion in order to create a glide path towards a ban on tire warmers, which will continue next year with another drop of 20°C to a maximum of 50°C for blankets. It’s a sensible move that addresses the big concern about banning tire covers – the safety implications of lack of grip during the warm-up phase.
“It was our request to do this step by step because it [the tyre warmer ban] is a big change for the construction and the compound,” Mario Isola, F1 manager at Pirelli, told The Race.
“There’s a common idea that we just need to design different compounds and everything is fixed. It’s not like that because with these cars and their performance there is an estimated increase in pressure from cold to hot which could be over 12 psi and that makes the footprint completely different.
“You can’t start at very low pressure because you destroy the tire in a few corners. You have to start from a minimum pressure acceptable for the tire and then copy with the period when the pressure rises and then stabilizes.
“But that means we should probably start at 20 psi, or something, and then you go up to over 30 psi. So it’s a completely different situation and we have to design a new construction in order to make the footprint much more stable with a change in pressure.
Running F1 tires at 30 psi is clearly not an option, as that’s close to the family hatchback’s minimum pressure level.
Pirelli Formula 2 tires, which are also low profile tires fitted to 18 inch rims from 2020, typically increase 6-7 psi from around 14 psi to 20-21 psi.
“If we have to make the same assumption on F1 tires and F1 cars, that means we have to increase the minimum pressure, and that means we have a pressure delta from cold to hot that is much higher,” Isola explains. . ” It changes everything.
“So it’s about designing a new construction and designing new compounds with a much wider working range, because you need grip from 20-30°C up to 120-130°C, because I imagine that they will stabilize in terms of temperature at a level similar to what we have now.
“We have to design tires with compounds capable of operating at 20°C and 120°C, that’s the risk. The risk is that if you have to find a compromise, you may have to sacrifice the warm-up phase to make it more difficult, or you have to accept that at some point the tire will overheat.
“That’s why we want to take it step by step, because now we have a good product that can deliver what we were looking for. It gives riders the opportunity to push and push and we don’t want to go back to a situation where riders are complaining about overheating or a slower warm-up. There are many elements that we have to take into account in the 2024 tires.”
If Isola seems a bit vague on tire specs, that’s because Pirelli has limited testing and has so far focused on 2023 tires. These are now widely approved and Pirelli thinks some elements of the The ’23 tire testing program will be relevant to the ’24 rubber, but the real work will be done next year.
The hope is that the tires without cover will remain largely unchanged in terms of shape, given the significant aerodynamic effect they have on cars.
Thus, the desire is to achieve the necessary characteristics primarily with construction and compounds. How tires warm up depends on a myriad of factors, but how the tire is presented to the track and how it is driven will make it work in a certain way and help raise the temperature. The key here is not the surface temperature, but the temperature inside the compound and at the core.
“We mainly work on the materials and the geometry more than the profile, because when you change the profile you have a big impact on the downforce of the car.
“It’s clear that when you change certain elements of the construction, even if you don’t change the whole profile, you have a slight change in the tire itself. But usually this is limited.
“Who is the ideal target? The ideal goal is to have a footprint with as even a pressure distribution as possible that does not change with this change in pressure and temperature. Obviously, this is an ideal world.
“With temperature, clearly having exactly the same footprint, the same pressure distribution, the same temperature distribution when going from 20°C to 120°C, it’s almost impossible.
“So we are working with new concepts to minimize these changes. Avoiding any change is impossible, minimizing it is what we try to do.
The weight of the cars is not a particular concern for Pirelli, although he is aware that stiff and low cars have an effect on the tyres. However, this should be well understood by the time the 2024 Pirelli tires are to be finalized.
What really matters is how the tires work in the crucial phases of the race. Since the refueling ban in 2010, the undercut has generally been the method of choice for gaining positions in the pit stop phases. With rare exceptions, the value of running longer is creating a significant lag in tire age or adopting a different strategy. Banning tire coverage could change that and make one-lap overcuts more achievable.
“To make a good prediction is not easy, but I can imagine that we would have a warm-up phase which would be longer,” explained Isola.
“The strategy will be different, but to give you a proper answer on the difference is a bit early.”
There was little evidence this year that reducing tire casing temperatures had a significant impact in the pit stop phases, although it did make the warm-up phase a little trickier. But depending on the characteristics of the new tires, the impact on strategy can be minor or profound.
What needs to be resolved is exactly what teams will or will not be allowed to do with their tyres. The current rules state that blankets are the only tire warming devices permitted and it is likely that the 2024 regulations will simply state that no tire warming devices are permitted.
But it will probably be necessary to create additional guidelines on what can and cannot be done. Isola thinks it will be important to get a good grasp of these, along with other ways to monitor tire parameters.
“I remember, for example, we had a similar situation many years ago with GT tires and teams would put the tires in the sun to try to raise the temperature and do weird things like that,” says Isolated. “Also, in F1 a few years ago they used the heat from the brakes to warm up the tyres.
“We probably also have to find a new system to control with regard to the minimum pressure, because with all these changes it is not easy to use the system we currently have in place.
“I think the tire regulations when we go to avoid the covers will be another important discussion that we need to have with the FIA and the teams.
This will likely include guidelines for tire temperatures to be within a certain ambient temperature range, which is similar to the rules for fuel temperature. But it remains to be seen exactly how these are framed.
What is clear is that there is still a long way to go in the development of 2024 tires, but the tire blanket temperature glide path is a sensible way to approach it that should ensure that the security issues typically associated with such moves will at least be mitigated.
But as to what impact it will have on the race, apart from the expectation that it will have an impact around pit stops – as well as how the tires are prepared for qualifying – the answer to that is not will start to emerge only when teams can test something close to the finished product for 2024.