For each race weekend, Pirelli nominates three dry compounds based on a number of factors. Certainly, these include the expected temperatures, the setting and above all the condition of the asphalt surface, which have a significant influence on the performance of the tyres. But even more important are the layout and the specific characteristics of the circuit, measured through a series of parameters that Pirelli discloses before every Grand Prix.
• Asphalt abrasiveness: this indicates how abrasive the track asphalt surface is and therefore how much of an impact it has on tyre wear.
• Asphalt adhesion: this indicates how much grip you can expect from the track, based on both the characteristics of that particular type of asphalt and on external factors such as whether sand is present, or the frequency of use of the circuit (is it permanent? Is it in a city?)
• Traction: this indicates how demanding the layout of the circuit is in terms of traction phases, i.e. when the tyre has to push the vehicle forward, especially when exiting slower corners.
• Braking: this indicates how challenging the circuit is for braking, when the tyres have to work together with the brakes to make sure the vehicle slows down.
• Lateral forces: this indicates how demanding the circuit is in terms of lateral forces, which affect the car especially when cornering: here the task of the tyres is to keep the car on track, resisting the forces that push it towards the outside at high speed.
• Tyre stress: this indicates the extent of the loads and speeds the tyres are subjected to along the circuit.
• Downforce: this indicates the level of aerodynamic forces pushing the car down. Downforce varies depending on how the teams configure the wings and other aerodynamic devices.
• Asphalt evolution: this indicates how much the conditions of the track are subject to changes during the weekend due to the amount of tyre rubber that is deposited on the track. This aspect is directly related to the level of abrasiveness of the asphalt and which compounds have been nominated.