In the middle of the ongoing silly season, Heiki Kovalainen substituted at Renault for compatriot Kimi Raikonen, who successfully underwent back surgery. Meanwhile a crack in Hamilton's chassis was discovered, which may explain his lacklustre performance in the recent races. Free practice one suffered a delay because dense fog prevented the medical helicopter from flying.

Quote Originally Posted by Practice 1
Pos Driver Team Time Gap Laps
1. Fernando Alonso Ferrari 1m38.343s 16
2. Jenson Button McLaren-Mercedes 1m38.371s +0.028s 25
3. Valtteri Bottas Williams-Renault 1m38.388s +0.045s 17
4. Esteban Gutierrez Sauber-Ferrari 1m38.532s +0.189s 18
5. Nico Rosberg Mercedes 1m38.657s +0.314s 21
6. Lewis Hamilton Mercedes 1m38.979s +0.636s 21
7. Felipe Massa Ferrari 1m39.005s +0.662s 17
8. Mark Webber Red Bull-Renault 1m39.083s +0.740s 17
9. Nico Hulkenberg Sauber-Ferrari 1m39.158s +0.815s 17
10. Pastor Maldonado Williams-Renault 1m39.200s +0.857s 15
11. Romain Grosjean Lotus-Renault 1m39.238s +0.895s 13
12. Sergio Perez McLaren-Mercedes 1m39.256s +0.913s 17
13. Heikki Kovalainen Lotus-Renault 1m39.487s +1.144s 18
14. Adrian Sutil Force India-Mercedes 1m39.699s +1.356s 15
15. Paul di Resta Force India-Mercedes 1m39.836s +1.493s 15
16. Daniel Ricciardo Toro Rosso-Ferrari 1m39.863s +1.520s 19
17. Daniil Kvyat Toro Rosso-Ferrari 1m40.065s +1.722s 20
18. Sebastian Vettel Red Bull-Renault 1m40.662s +2.319s 21
19. Alexander Rossi Caterham-Renault 1m41.399s +3.056s 21
20. Max Chilton Marussia-Cosworth 1m41.605s +3.262s 19
21. Charles Pic Caterham-Renault 1m42.054s +3.711s 19
22. Rodolfo Gonzalez Marussia-Cosworth 1m43.716s +5.373s 17

US GP: Fernando Alonso leads bizarre first practice for Ferrari - F1 news - AUTOSPORT.com
Quote Originally Posted by Practice 2
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

US GP: Sebastian Vettel goes fastest in second F1 practice - F1 news - AUTOSPORT.com