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Sebastian Vettel set the fastest time of second practice for the United States Grand Prix as Red Bull laid down a marker in Austin.

Having carried out high-fuel runs during a shortened morning session, Vettel was immediately on the pace at the start of FP2 and eventually set a soft tyre time of 1:37.305. That left him 0.115s clear of team-mate Mark Webber, with the Mercedes pair of Nico Rosberg and Lewis Hamilton Red Bull's closest challengers but half a second off Vettel.

Rosberg ended the session 0.173s ahead of Hamilton, with the latter complaining that he still is not getting the most out of the car as he requested more laps on low fuel. Hamilton ended up just over 0.1s faster than his ex-McLaren team-mate Heikki Kovalainen, who impressed with the fifth fastest time at the end of his first day for Lotus.

Red Bull's long-run pace was once again impressive, with Vettel consistently lapping around half a second quicker than Hamilton as both completed stints on the medium tyre and Webber was comfortably faster than the pair of them on the hards.

Having set the pace during FP1, Fernando Alonso and Ferrari struggled in the warmer temperatures of the afternoon. Alonso was over a second off the pace in 10th place, with Felipe Massa another half a second further back in 12th. Williams also looked to be struggling, with Valtteri Bottas in 16th and Pastor Maldonado - "very happy" to be leaving the team - down in 18th and complaining that "everything is wrong".

Marussia opted for a different approach to FP2, staying on high fuel throughout the session and running around nine seconds off the overall pace. Having completed 31 laps, Max Chilton's day came to an end 10 minutes early as he spun off at the final corner and climbed out of a car with burning brakes.

In a slightly comedic turn of events, it took the marshals a long time to remove the car as it was hoisted up and down on the recovery crane, causing Nico Hulkenberg to radio in: "Jesus, how long do they need to get that car out of the way?"

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