During the announcement of the FIA’s 2026 rules, a significant statement was made regarding the performance goals of the next generation of Formula 1 cars. The section discussing the narrower tires mentioned the objective of maintaining grip with minimal loss. While this may sound simple, achieving it is not as straightforward due to the reduction in width of the front and rear tires. The front tires will be 25mm narrower, representing an 8.2% reduction, while the rear tires will be 30mm narrower, a reduction of 7.4%. This reduction is necessary to decrease drag by 55%. FIA single-seater technical director Jan Monchaux assures that this target has been discussed and agreed upon with Pirelli, F1’s tire supplier. However, delivering on this objective will still be challenging, especially considering the additional goal of reducing the weight of a set of tires by four-to-five kilograms, bringing it to approximately 46kg. Additionally, the diameter of the tires will be reduced by seven millimeters.
One change in the 2026 tire development program that will make it easier is the decision to abandon the plan of switching to 16-inch wheel rims. Initially, this change was intended to reduce weight. However, it was discovered that it would not have a significant impact on weight reduction, and Pirelli was concerned that it would make it more difficult to address overheating issues and temperature sensitivity. Pirelli F1 boss Mario Isola explains that staying with 18-inch tires was accepted as a proposal to address these concerns.
Testing of the prototype tire is scheduled to begin in September, with a deadline for final approval set for 12 months later. Pirelli is currently using simulation tools to design the prototype but acknowledges that on-track testing will be crucial. FIA single-seater director Nikolas Tombazis states that Pirelli has been given increased opportunities and time for development. However, the testing will still be conducted using mule cars, which are not an exact representation of the 2026 cars. Pirelli has faced similar challenges in the past when developing tires for new car designs. Isola explains that the mule cars will be adapted as much as possible but will still have the current aero package and dimensions. Adjustments will be made to tune the level of downforce to align with expectations for 2026, but certain features like the X-mode and Z-mode settings cannot be replicated in the real world.
Pirelli plans to build physical prototypes in the summer for indoor facility testing to assess durability and pressure usage. They also aim to conduct three test sessions by the end of the season, two in dry conditions and one in wet conditions, to advance the development of the 2026 tires. The construction of the tires needs to be finalized by September 1st, leaving limited time for development.
The exact form of the mule cars for testing is still uncertain, as teams have cars of various ages that could be adapted. However, the inability to simulate the transition between high- and low-drag modes is a limitation of the mules. Pirelli has experience with sudden load changes due to the DRS, but the transition between X and Z-mode in 2026 will be more extreme. Isola acknowledges that simulation can provide some understanding of this transition and overall tire performance, but real-world testing with the 2026 cars is necessary.
Pirelli recognizes that maintaining minimal grip loss is a challenging objective, and while they are confident in their abilities, the laws of physics dictate that there will inevitably be some reduction in grip. With corner speeds being closely examined, the performance of the tires could become a topic of discussion in the early stages of the 2026 season.