Not just engines and aerodynamics: with the new regulations the tires also change

The 2026 regulatory change is defined by many as the greatest technical revolution of the last thirty years. The innovations embrace every area, including Pirelli tyres, which are different from the previous ones in size, compounds and structure. The free design of the rims also returns, an opportunity that the teams are ready to exploit to develop better management of tire temperatures, a task that could have an extra complication with the new cars. Smaller wheels The initial proposal for the new technical cycle was to move to 16-inch diameter rims, which would have helped to further reduce the weight of the single-seaters, one of the priorities for the 2026 regulations. Following evaluations, however, it was preferred to continue on the 18-inch path, but with some changes. The 2026 tires are slightly narrower than the previous ones, to be precise by 25 and 30 mm at the front and rear respectively, with a reduction of about ten millimeters on the external diameter. The changes help improve efficiency and save a few pounds, with a weight of 10.4kg for the single front tire and 12.8kg for the rear, for a total of 46.4kg for a complete set of slicks. The new Pirelli range forces teams to learn about them, studying all their facets. The change in size, in fact, causes the shoulder of the tire to deform differently when the car is moving, with aerodynamic implications. It therefore becomes a priority for the teams to analyze in the wind tunnel what this entails at the level of the vortices that are generated near the contact mark of the wheel with the ground, which in turn influence the performance of the surface. From a thermal point of view, however, smaller tires tend to work at higher operating temperatures, an aspect on which, however, conflicting reports have been received. Rims to manage temperatures During the development of the 2026 product, Pirelli received comments from some teams that in certain contexts it may be difficult to heat the front tires sufficiently. On the one hand, the drastic reduction in aerodynamic load in a straight line given by the active aerodynamics, three times more powerful than the old DRS, reduces the crushing of the tires on the ground, generating less heat inside them. Furthermore, the higher speeds expected on the straight cause the air to cool the tires more, also aided by their smaller size. The apprehension is especially for circuits characterized by long straights, with the fear of braking with the front not up to temperature. In Las Vegas and Baku, for example, the old Pirellis cooled by over 40°C at the front on the straight, a value that could be even higher in 2026. Managing tire temperatures will be crucial, as it always has been in Formula 1, but this time, in addition to combating overheating and thermal degradation, particular attention will need to be paid not to drop below the operating window. An important tool available to the teams are the rims, which, contrary to the ground effect regulation cycle, are no longer subject to the standard supply. The teams can thus try to design them in such a way as to exploit the heat of the braking system to bring the tires up to temperature and/or study the fluid dynamics inside the wheel to promote cooling. Thus, an important challenge ground returns which in the past attracted quite a bit of attention, as was the case of Mercedes’ drilled hubs in 2019. The new Pirelli tires for the 2026 season Back to the five compounds For 2026 Pirelli has also rethought the compounds, initially developing six specifications, but then homologating only five given the small gap between the C5 and the C6. As Mario Isola, director of Pirelli Motorsport, explained to FormulaPassion last August, the main difficulty was understanding in advance whether the product was too resistant or subject to excessive degradation for new cars: “When you have such a big change in the regulations, the risk is of going either too hard or too soft, due to having overestimated or underestimated what they told you. The reason why I also wanted us to work on six compounds is because we would like to homologate as many for 2026, trying to space them out as much as possible. This way, if we realized we were too much on one side or the other, we could refocus ourselves a bit with the selection of compounds for each race”. Pirelli has also continued the work of widening the operating window, the effectiveness of which will depend greatly on the characteristics of the individual cars. However, the proposal to eliminate tyrewarmers for dry tyres, the ban on which remains valid only for wet tyres, was not followed up on. In this regard, the Milanese company has tried to move the transition point between full wet and intermediate, in an attempt to make the extreme wet tires usable before the conditions worsen to the point of making visibility critical. Furthermore, Pirelli has tried to develop a more rigid wet product, so that, even in the event of deactivating the active aerodynamics for safety reasons, the greater aerodynamic load does not excessively crush the car to the ground and wear out the plank board. Photo by Beata Zawrzel/NurPhoto via Getty Images The construction is also new. Along with the dimensions and compounds, a further novelty is represented by the structure, another change that contributes to altering the deformations of the rubber and its impact on the aerodynamics of the car. “We worked as usual to find light but resistant constructions, in order to keep the pressures in line with current levels,” explains Isola. “This is because, by making the tire smaller, to give it the same ability to support the load, the pressure must be increased. We tried to work on some innovative material and concept that would allow us to maintain similar pressures, despite the small size of the tires and the loads that are not so monstrously far from the current ones”. Overall, the development of the 2026 product was certainly not simple for Pirelli, which corrected the objectives and project specifications as it received load estimates from the teams, who in turn corrected their work based on the latest grip estimates. There is therefore great curiosity to see which concept will be the most effective in making the new tires work, yet another variable in a 360° regulatory revolution. It will be a Formula 1 to be discovered gradually, where the rapid learning curve will promote an evolution of the balance of power, which in the middle of the season is unlikely to be the same as the first race.