What happened: Fifty minutes into the 60-minute second practice session at Circuit of the Americas, Pierre Gasly, who passed 50,000 career Formula 1 kilometers at Barcelona in June, held 12th on the timing sheets while teammate Franco sat 15th. Earlier at the 30-minute mark, Alpine split its tire work with Gasly running on soft compounds and Franco logging continuous laps on hards.

Why it matters: Splitting the soft and hard compounds across the two cars gives Alpine comparative tire-degradation data ahead of Sunday's Round 18 race in Austin. Most of the grid pitted with 25 minutes remaining to transition from single-lap pace to high-fuel runs as sunset approached.

What to watch: Teams return to Circuit of the Americas for final practice and qualifying to lock in grid positions for the United States Grand Prix.