Lewis Hamilton topped a wet first practice session for the United States Grand Prix by more than a second as Ferrari focused on mileage in the tricky conditions.
After heavy rain made for a wet session throughout, the championship leader only completed six laps but still managed to finish comfortably clear of the field after registering a 1m47.502s. That was more than 1.3s faster than teammate Valtteri Bottas managed in second place, with the Finn only completing one lap more than Hamilton as Mercedes did little running.
Max Verstappen also failed to reach double figures in terms of laps but was a close third behind Bottas, with just 0.041s separating him from the second Mercedes. It was a case of two-by-two with Daniel Ricciardo fourth ahead of the Ferraris, but the Scuderia was by far the busiest team of the top three.
Sebastian Vettel had a small off-track moment when he ran wide at the Turn 11 hairpin but ended up completing 18 laps, suggesting a higher fuel load and specific testing taking place. Although he was nearly two seconds off the pace, Vettel was half a second faster than Kimi Raikkonen who was running a new floor during FP1. Vettel used the old floor as part of a direct comparison despite the conditions.
The rest of the field was over three seconds adrift of Hamilton despite the majority of drivers reaching double figures, with Carlos Sainz in seventh ahead of Romain Grosjean, Charles Leclerc and Marcus Ericsson.
The session was delayed for a little over 10 minutes after Leclerc spun off at Turn 8, with the Sauber driver recovering through the gravel to rejoin the track. In doing so, Leclerc deposited a lot of debris on the racing line at Turn 9 and the session was red flagged to allow track cleaning to take place before continuing.
Just outside the top 10 were the McLaren pair of Fernando Alonso and Lando Norris, with just under 0.2s separating the two in wet conditions. Then came Pierre Gasly who was using a further modified Honda power unit that will see him start from the back of the grid.
More wet weather is expecting for FP2, while Saturday is also forecast to be wet in Austin — meaning Sunday’s race could be the first time any dry running takes place.