US GP: Sebastian Vettel goes fastest in second F1 practice

Following the disjointed morning session hampered by both fog and a failed medical helicopter, the Formula 1 teams were able to get plenty of trouble-free running in the afternoon.

To little surprise, Vettel was the pacesetter for most of the session.

He was swiftly down to a benchmark 1m38.211s lap on the hard tyre.

Although Nico Rosberg and Webber popped in front by switching to mediums sooner, Vettel's 1m37.305s on the softer rubber put him on top again.

Webber ended up 0.115 seconds slower in second, both Red Bulls having shown good long-run pace too.

Rosberg remained best of the rest in third, ahead of Mercedes team-mate Lewis Hamilton.

Lotus's new recruit Heikki Kovalainen managed to complete 41 laps as he got used to Kimi Raikkonen's former seat, and was an impressive fifth quickest. The Finn was 0.182s faster than team-mate Romain Grosjean in eighth.

Sauber had a strong day as Esteban Gutierrez repeated his rapid morning form in sixth, followed by team-mate Nico Hulkenberg.

Jenson Button's McLaren and Fernando Alonso's Ferrari completed the top 10.

Williams had been rapid in practice one, but Valtteri Bottas was only 16th in the second session, with team-mate Pastor Maldonado two places further back and quick to express his unhappiness via team radio.

Much of the final part of the session ran under yellow flags after Max Chilton went off at the last corner with what he suspected was a brake failure on his Marussia.

The tractor vehicle sent to recover the car got into some difficulty, before finally managing to clear the car away.

Pos Driver                Team                   Time      Gap      Laps
 1. Sebastian Vettel      Red Bull-Renault       1m37.305s           35
 2. Mark Webber           Red Bull-Renault       1m37.420s  +0.115s  37
 3. Nico Rosberg          Mercedes               1m37.785s  +0.480s  38
 4. Lewis Hamilton        Mercedes               1m37.958s  +0.653s  38
 5. Heikki Kovalainen     Lotus-Renault          1m38.073s  +0.768s  41
 6. Esteban Gutierrez     Sauber-Ferrari         1m38.229s  +0.924s  40
 7. Nico Hulkenberg       Sauber-Ferrari         1m38.254s  +0.949s  40
 8. Romain Grosjean       Lotus-Renault          1m38.255s  +0.950s  33
 9. Jenson Button         McLaren-Mercedes       1m38.269s  +0.964s  34
10. Fernando Alonso       Ferrari                1m38.461s  +1.156s  33
11. Adrian Sutil          Force India-Mercedes   1m38.719s  +1.414s  31
12. Felipe Massa          Ferrari                1m38.938s  +1.633s  37
13. Sergio Perez          McLaren-Mercedes       1m38.941s  +1.636s  31
14. Daniel Ricciardo      Toro Rosso-Ferrari     1m39.246s  +1.941s  28
15. Paul di Resta         Force India-Mercedes   1m39.410s  +2.105s  34
16. Valtteri Bottas       Williams-Renault       1m39.512s  +2.207s  37
17. Jean-Eric Vergne      Toro Rosso-Ferrari     1m39.579s  +2.274s  36
18. Pastor Maldonado      Williams-Renault       1m39.784s  +2.479s  33
19. Charles Pic           Caterham-Renault       1m40.376s  +3.071s  39
20. Giedo van der Garde   Caterham-Renault       1m40.563s  +3.258s  35
21. Max Chilton           Marussia-Cosworth      1m46.226s  +8.921s  31
22. Jules Bianchi         Marussia-Cosworth      1m47.009s  +9.704s  20