Teams consulted over 2026 tyre size following previous complaints

F1, the FIA and the 10 teams have agreed the tyres will remain 18-inch in size when the new power unit regulations are introduced in 2026.

Towards the end of last year, it emerged that the FIA and F1 were looking at ways to make the cars significantly lighter from 2026. 

One of the solutions suggested was reducing the current 18-inch tyres to 16-inch. Mercedes technical director James Allison was not a fan of the fact that Pirelli and F1 were thinking about this rather than the teams.

"It's not easy to reduce weight," Allison told select media, including RacingNews365 last year. "It is extremely difficult to come up with technical rules that make the car much lighter. I think the way to make the car lighter is to lower the weight limit and make it our problem. 

"When cars go over the limit, it forces us all to make tough decisions about what we do and don't put in our cars. Not everyone agrees with that position, but I think it's the best way to achieve weight reduction."

During Pirelli's special tyre test at Suzuka recently, the focus was on next year's rubber. Pirelli motorsport director Mario Isola informed select media, including RacingNews365, what the goals of the test were and its upcoming objectives.

"We wanted to finalise the tyre construction needed for 2025," said Isola. "We know how the teams are developing their cars and the 'stress' the tyres have to endure is increasing. Our next objective is to reduce overheating to such an extent. 

"These two objectives are mainly focused on 2025, but we are also already looking at 2026 with an oblique eye, but that again is mainly focused on tyre size and character."

Pirelli has been listening

According to Isola, Pirelli is therefore going to focus as soon as possible on testing the new tyres for 2026.

"We are currently anticipating the start of developing the 2026 tyres," Isola added. "Hopefully we can start testing in September or October, so we can start collecting new information by then." 

For Pirelli, the coming period will be dominated by the completion of the 2025 tests. Isola added: "We will have another wet-tyre test at Paul Ricard and we will test after Monza and Silverstone, among others. To that will hopefully be added a separate test at Mugello." 

In contrast to the comments from Allison, Pirelli does appear to have listened to the requests of the teams to be more involved in the decision-making process. 

According to Isola, the choice for 2026 has already been made. He said: "We have agreed with the FIA and the teams that we will stay with the 18-inch tyres.

"This is for a number of different reasons, mainly the carrying capacity and character of the current tyres. We believe that a 16-inch tyre would fall short on both counts."

Isola is referring to the proposed strengths the new 2026 regulations should bring. The planned 2026 regulations, combined with 16-inch tyres, would, in Isola's eyes, not result in good performance. 

"When I look at the provisionally calculated performance of the 2026 cars, factoring in the increase in overheating and also an expected loss of durability, it means that we are throwing up the tyre pressure unnecessarily," he said.

"That's why, after analysing the data, we talked to the teams and FIA and decided to keep the 18-inch tyres. The teams ultimately agreed to that as well."