F1 set to retain 18-inch rims in 2026, with tyre adjustments

Formula 1 will likely retain its current 18-inch wheels for the 2026 season after plans for a switch to 16-inch rims were rejected following a recent meeting of the FIA's technical advisory committee.

The initial proposal for smaller rims was rooted in the FIA's ongoing push to make 2026 cars lighter, with a weight reduction generally translating into faster lap times and potentially more exciting racing.

However, tyre supplier Pirelli expressed concerns about the feasibility of the switch.

Formula 1’s exclusive tyre supplier’s reservations were twofold. Firstly, a significant production line overhaul would have been necessary to accommodate the new size. Time was also a factor, as this change would necessitate extensive testing with prototype cars in 2025 – a tight timeline for such a major shift.

Secondly, Pirelli worried about the potential negative impact on F1's image. The sport's 2022 switch to 18-inch wheels and lower profile tyres followed a trend adopted by the automotive industry at large, and a reduction could be perceived as a backward step.

Furthermore, a new size would create extra challenges for teams already adapting to the significant technical regulation changes coming in 2026.

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While the 18-inch rim size remains, the committee did agree to slight modifications to the tyre profile.

This compromise aims to achieve some of the weight reduction benefits originally sought with a smaller size while minimizing disruption for Pirelli and the teams. The specifics of these adjustments are expected to be officially announced soon.

"We are close to the final version of the sizes," sayd Pirelli F1 boss Mario Isola, speaking to Motorsport.com.

"Obviously when you design the wheel, you have to consider all the package, brakes, wheel, suspension, tyre, so I believe we are close to the final sizes.

"We have to change because the new car is different, and in any case, we have to design a smaller tyre.

"The discussion is between 16 and 18-inch tyres. And our preference is to stay on 18-inch tyres. And I believe that there are valid reasons to stay on 18-inch, with smaller tyres, but still the same rim.

"That's what we are discussing, just a bit smaller diameter, a slightly lower profile and slightly narrower tyre."

Regarding weight as a factor that would justify a switch to 16-inch wheels, Isola minimized its importance.

“There is an element that is weight," explained the Italian. "And clearly that affects all the package, and also the wheels. The difference between 16 and 18 and a narrow 18 is not huge. So the weight element is there.

"But it's not the only element. There is an element of performance. Because obviously if you were to go to 16-inch tyres, much smaller, the risk of overheating is much higher. A smaller diameter means that you disperse the heat in a different way.

"And so there are many elements that if we wanted to design a tyre that is in line with drivers' expectations. For performance, the 18-inch tyre is better than the 16."

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