Tyre degradation

Tyre degradation describes how a race tyre's performance falls off over the course of a stint, distinct from an outright failure like a puncture. Two mechanisms drive it: physical wear, the gradual loss of tread and compound, and thermal degradation, where sustained heat changes the rubber's grip characteristics even before wear becomes severe.

Teams model degradation as a curve of expected lap-time loss per lap through a stint; most compounds degrade gradually, though some show a sharper "cliff" where performance drops suddenly once a threshold is crossed. This is distinct from the lap-time gains a car shows simply from burning off fuel, so engineers separate the two effects when reading raw lap times from motorsport telemetry, since fuel and tyre effects move in opposite directions across a stint.

Degradation modeling is central to pit strategy: teams weigh the lap time a worn tyre is losing against the time cost of an additional pit stop to decide stint length and compound choice, drawing on race pace analysis from practice sessions. A common pitfall is trusting practice-session degradation trends too literally on race day, since practice runs often use different fuel loads and track conditions, particularly rubber laid down on the racing line, that shift how tyres actually behave once the race begins.