The Circuit of the Americas is tough on tyres, but this year it was more so. The bumps had developed further since they first became apparent in 2019 as the soil beneath has expanded and contracted heavily in the extreme heat and sudden heavy rain the place gets through the year.
So thermal degradation was the dominant mechanism of the race we saw, to an even greater extent than has previously been the case here. The tyres undergo very high loadings for a long time through Turns 3/4/5/6 and then again through the long, double-loop of 17/18. In both cases these workouts are followed by corners demanding acceleration from low speed. The rear tyres do not get an adequate chance to recover and are constantly having to be prevented from reaching excess temperatures by the driver. The bumps, especially those through Turn 8, were extreme and the constant expansion/ contraction of the sidewalls created by them just added yet more heat to the tyre.
“Three stops would have been slow, and one stop was impossible”