Red Bull Racing maintained its grip on the timesheets at Austin’s Circuit of the Americas, with Sebastian Vettel quickest in final practice ahead of team-mate Mark Webber.

The Red Bull pairing were the only drivers to dip below the 1m37s mark as the field conducted performance runs on the medium tyre at the end of the session. Vettel’s 1:36.733 was good enough for P1, with Webber finishing two tenths of second further back. Lewis Hamilton took P3 for Mercedes, just over three tenths adrift of champion elect Vettel.

The longer first phase of the session, conducted on the prime hard tyre, was also dominated by the Red Bulls. When, 40 minutes into the session, the field retired to the garages to make the switch to option tyres, Vettel was at the top of the order with a hard-tyre lap of 1:37.433, with Webber in P2, just under two tenths down on his team-mate.

Nico Hulkenberg looked strong for Sauber in fourth place, half a second down on Vettel’s benchmark, while Romain Grosjean took a solid fifth position for Lotus.

Behind them Jenson Button was sixth, the competitiveness on display from his McLaren making the three-place grid penalty he received on Friday for overtaking under red flags all the more painful. Seventh place went to Nico Rosberg in the second Mercedes, with Sergio Perez eighth in the second McLaren. Ninth position was taken by Valtteri Bottas, showing good pace in an improved Williams, and 10th position went to Force India’s Adrian Sutil.

United States Grand Prix Free Practice Three times
1 Sebastian Vettel Red Bull Racing 1:36.733
2 Mark Webber Red Bull Racing 1:36.936 +0.203
3 Lewis Hamilton Mercedes 1:37.064 +0.331
4 Nico Hülkenberg Sauber 1:37.272 +0.539
5 Romain Grosjean Lotus 1:37.345 +0.612
6 Jenson Button McLaren 1:37.534 +0.801
7 Nico Rosberg Mercedes 1:37.578 +0.845
8 Sergio Pérez McLaren 1:37.583 +0.850
9 Valtteri Bottas Williams 1:37.747 +1.014
10 Adrian Sutil Force India 1:37.748 +1.015
11 Fernando Alonso Ferrari 1:37.763 +1.030
12 Esteban Gutiérrez Sauber 1:37.774 +1.041
13 Heikki Kovalainen Lotus 1:37.879 +1.146
14 Pastor Maldonado Williams 1:38.022 +1.289
15 Daniel Ricciardo Toro Rosso 1:38.109 +1.376
16 Paul di Resta Force India 1:38.275 +1.542
17 Felipe Massa Ferrari 1:38.408 +1.675
18 Jean-Eric Vergne Toro Rosso 1:38.636 +1.903
19 Charles Pic Caterham 1:39.578 +2.845
20 Giedo van der Garde Caterham 1:40.056 +3.323
21 Jules Bianchi Marussia 1:40.825 +4.092
22 Max Chilton Marussia 1:41.293 +4.560