The FIA has mandated a final vote on whether to ban tyre warming blankets from Formula One must take place on or before July 31st this year. As part of the International organisations push for net zero by 2030 the FIA has been pushing for the complete removal of tyre warmers from Formula One.
The maximum temperatures have been slowly reduced over the past couple of seasons from 100 degrees celsius to 70 for the front and 80 for the rear.
Mario Isola – Pirelli boss
Pirelli abandon 2023 changes
This year there was a mandated further reduction to 50 degrees Celsius though this was abandoned following the tyre test during the USA Grand Prix where a number of drivers were critical of the new Pirelli rubber.
Max Verstappen was one of the loudest voices complaining about the lower temperature pre-heated tyres.
“It was not enjoyable. I drove on 50 degrees and I almost spun in the pit lane. I also had the hardest compound but I think there is a lot more to it,” said the Red Bull racer, adding: “I think we will have a lot of crashes, that I know already.”
WhIlst Red Bull give their current dominance of the sport have a vested interest in keeping as many things the same as possible, Lando Norris also believes the tyres were not safe.
Norris: Tyres not pre-warmed “unsafe”
“It’s an unsafe thing rather than it just doesn’t feel as nice to drive,” the British driver told the assembled press.
”A current era F1 car, which is designed so specifically with all the aero and stuff, it’s not made to go out on cold tyres. Once you go to a much colder race track, or if it is a little bit damp or something, everyone is going to shunt the car at some point.
“No driver wants it, basically.”
And Norris is spot on. The tyres in Formula One are an integral part of the aerodynamics of the car something the F1 team’s are learning this year.
“Not dangerous” says Pirelli boss
Changing temperatures and high speed low speed circuits play to the different strengths of the cars – other than Red Bull – switching the order around between Mercedes, Aston Martin, Ferrari and Alpine in the chasing pack.
Pirelli boss Mario Isola confirmed Pirelli would “listen to drivers” and scrap the 50 degrees plan in 2023. But the tyre maker still plans to get rid of the blankets completely in 2024, and will be creating brand new compounds to offset the grip problem.
“I don’t believe it’s dangerous, but in Austin, which is a high-energy circuit, we had some issues with the warm-up,” Isola explained after the test sessions.
“After listening to the drivers, we started to consider that if Austin is a high-severity circuit with very good weather conditions and they had an issue with a warm-up, what happens at street circuits, low-severity circuits with smooth Tarmac, or in poor conditions?”
Pre-warming time cut for 2023
Pirelli were still insistent the teams become less dependent on pre-warmed tyres for 2023 and decided to reduce the amount of time the rubber could be kept warm during each track session.
“If, instead of going down to 50°C, we cut one hour [of the currently-permitted three hours at 70°C] we discovered that it is a lot more efficient, we save more energy and we don’t create any issue with the warm-up.
“So the drivers can go out and push, as they are doing now. That’s why we decided in Mexico to test the blankets at 70°C for two hours instead of three hours.”
While the tyre compounds have changed from 2022 to 2023 its is now far more difficult for the teams to have the full range of tyres available to the driver at optimum temperature during the F1 races this season.
Tyre changes a reset opportunity
Again this could also be a factor in the week to week shift in which teams are experiencing tyre struggles this year.
The challenge for Pirelli to move to tyres in 2024 that require no pre-heating is monumental but it could be the big game changer the field behind Red Bull needs.
With the driver having to get the tyres up to their optimum operating temperature which is around 120-130°C, the tyre must now operate in a much larger temperature range.
The tyres at ambient temperature may be around 10-20°C unlike their pre-warmed predecessors now at 70°C.
New tyres different aero effects
The problem is tyre pressure. As a tyre warms up the pressure inside the tyre increases. So for a tyre going from 10-20°C up to
120-130°C there is a significantly greater increase in pressure than from the preheated tyre where the temperature change is around 50°C.
As Isola explains, the challenge is “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.”
“We have to design tyres with compounds able to work at 20°C and at 120°C, which is the risk.
“The risk is that if you have to find a compromise, maybe you have to sacrifice the warm-up phase so that is more difficult, or you have to accept that at a certain point you overheat the tyre.”
Tyre pressure rise set to double
At present the tyre pressures from pre-warmed to operating temperature rise about 5-6°C. But for a colder starting tyre the pressure rise would double and with the current tyre construction change the profile of the tyre significantly.
“You cannot start at a very low pressure [say 15°C] because you destroy the tyre in a few corners”, Isola explains.
“You need to start with a pressure that is the minimum acceptable for the tyre then copy with the period in which the pressure is growing then stabilising.”
However, it is inevitable that the bigger rise in pressure which the non-pre-warmed tyres will experience, will inevitably change the footprint of the contact patch with the asphalt.
New tyre footprint could nobble Red Bull
This in turn will alter the crucial front of the car airflow in ways the current cars are not experiencing. Further as Red Bull have demonstrated the tyres are key to the entire aerodynamics of the car including the underfloor low pressure channels.
Here such a big change from pre-warmed to ambient temperature tyres could easily nobble the current aero design which is creating such dominant car for Red Bull Racing.
The effect of the new Pirelli tyres could very well have as big an effect as the 2022 aerodynamic rules changes brought in by the FIA.
Mercedes’ Lewis Hamilton has been a naysayer when testing the new non pre-warmed Pirelli rubber earlier this year.
Hamilton may change his tune
“I’ve tested the no blankets [tyres], and there is going to be an incident at some stage. So, from a safety factor I think it is the wrong decision,” said Hamilton.
The vote in July will require a simple majority from the team which in reality means 5 out of 10 must vote in favour of the new Pirelli rubber.
Given the distance Mercedes and the rest are behind Red Bull, there is no other hope on the horizon before the new power units arrive in 2026 that any team can close that gap to Red Bull over the next two seasons without a big regulation change, which banning the tyre warmers may just be.
And so Lewis Hamilton may change his tune in the coming weeks when questioned over the new Pirelli tyres that have been tested for two days this week in Barcelona by Mercedes and Ferrari.
A three-way battle for the ages! ⚔️
— Formula 1 (@F1) June 7, 2023