Pirelli has been Formula 1's sole tyre supplier since 2011. Their compound range — designated C1 through C5, where C1 is hardest and C5 softest — determines the strategic shape of every grand prix weekend. Understanding how the compounds work, and why their selection matters, reveals much about F1 strategy.
For each round, Pirelli nominates three adjacent compounds from their range and labels them Hard, Medium, and Soft. The specific selection varies by circuit energy level: high-energy tracks like Silverstone or Spa get harder compounds; lower-stress circuits like Monaco or Singapore get softer ones.
The core trade-off is straightforward: softer compounds generate more grip and pace, but degrade faster. Harder compounds last significantly longer but sacrifice pure speed. Teams must balance peak performance against strategic flexibility — choosing when to pit and which compound to use for each stint.
Tyre degradation is not linear. Compounds go through a warm-up phase, a performance peak, and then a degradation phase that can be gradual or sudden. The sudden end of a compound's working range — the "cliff" — is one of the most challenging elements to predict. Crossing it by even one lap can cause lap time losses of two to four seconds per lap as grip disappears rapidly.
Thermal management is continuous. Too cold and the compound won't generate sufficient mechanical grip. Too hot and the rubber blisters, chunks, or degrades catastrophically. Driving style, track surface texture, ambient temperature, and car setup all affect tyre temperature simultaneously.
The 2022 switch from 13-inch to 18-inch wheels fundamentally changed F1 tyre behaviour. The lower-profile sidewall of the 18-inch construction runs at lower operating temperatures, reducing the dramatic overheating failures that characterised parts of the earlier era.