SEBASTIEN VETTEL SENT an ominous warning with another stunning display in the second practice session at the United States Grand Prix.
Despite spending most of his time parked in the Red Bull garage due to mechanical problems, the defending champion was quickest again on Friday after clocking a time of one minute 37.718 seconds.
Vettel was three laps into his practice session at the Circuit of the Americas on Thursday before a water system fault was detected.
The German managed to return to the track and did so in fine fashion by finishing 0.757 seconds ahead of his nearest rival, team-mate Mark Webber.
Webber was second quickest, producing a time of 1:38.475 seconds. The Australian topped the standings early in the session before Vettel made his move.
Fernando Alonso of Ferrari placed third behind the Red Bull duo, while McLaren’s Lewis Hamilton and Jenson Button completed the top five positions.
Early leaders Felipe Massa (Ferrari) and Nico Rosberg (Mercedes) slipped to sixth and seventh respectively, with Bruno Senna (Williams), Kamui Kobayashi (Sauber) and Michael Schumacher (Mercedes) further back in the top 10.
