Commentators say a tyre is 'going off' as if it were one thing. It is not. A tyre can lose performance in two fundamentally different ways, and confusing them is the fastest route to misunderstanding a race. Learn the difference and a huge amount of strategy suddenly makes sense.
Thermal degradation: the tyre that overheats
A racing tyre works in a temperature window. Too cold and the rubber is hard and slippery; too hot and it starts to break down, the surface overheating until it loses grip. Thermal degradation is what happens when the tyre gets pushed past the top of that window.
The telltale sign is that the loss is partly recoverable. A driver suffering thermal deg can back off, let the tyre cool, and claw some performance back. That is why you hear engineers telling drivers to manage their pace — they are protecting the tyre from cooking itself. Thermal deg is driven by how hard the car works the rubber: aggressive driving, high downforce loads, hot tracks and abrasive surfaces all push temperatures up.
Wear: the tyre that runs out of rubber
Wear is simpler and crueller. It is the physical loss of tyre material as it grinds against the track. Unlike thermal deg, it does not come back. Once the rubber is gone, it is gone, and eventually the tyre reaches a cliff where performance falls off sharply and dangerously.
Wear is dictated by circuit abrasiveness, cornering loads and distance. Some tracks sandpaper the tyres down; others are gentle. A team can nurse a worn tyre for a while, but there is a hard limit, and crossing it is not a matter of managing pace — it is a matter of the tyre being physically finished.
Thermal degradation is a tyre that is too hot and can recover. Wear is a tyre that is running out and cannot. Strategy depends entirely on which one you are fighting.
Why the distinction decides races
Here is where it matters. If a circuit is thermally limited, the winning approach is management — keep the tyre in its window and it will last, so a driver with a gentle touch can stretch a stint far beyond what raw pace suggests. Fresh tyres help, but discipline helps more.
If a circuit is wear-limited, management only delays the inevitable. The tyre will hit its cliff regardless of how carefully it is driven, so strategy becomes about timing the stop before that cliff arrives and not being caught out on rubber that is about to collapse.
Reading it from the outside
You can often tell which is which from how a stint unfolds. A tyre losing time gradually, where a driver can lift the pace and recover some, is thermally limited. A tyre that holds steady and then falls off a cliff is wear-limited.
Understanding this is the key to decoding why the same strategy triumphs at one race and backfires at the next. The tyre compound might be identical; what changes is how it dies. And a strategist who knows whether they are fighting heat or wear is already a step ahead of one who just sees a tyre 'going off.'