Nico Rosberg continued his good form at the Circuit of the Americas and set the fastest time of the weekend during FP2 with Red Bull Racing driver Daniel Ricciardo taking second place ahead of second Mercedes driver Lewis Hamilton.
It was the Briton who topped the first practice session, but a brake issue did not allow him to get the best out of the super soft tyres in the second session. The Mercedes cars look strong and are favourite for pole position, but the Red Bull cars are keeping on their tails should they make even a slight error and fail to extract all the speed from their car.
Sebastian Vettel was fourth for Ferrari, but the Italian team looks to be the third best team yet again, as they continue to struggle to match the two teams ahead of them in the championship. Kimi Raikkonen was unable to set a time on the super-soft compound after going off track during his hot lap.
Williams and Force India are likely to resume their battle for fourth place in the constructors' championship but McLaren-Honda are also in the mix after Jenson Button and Fernando Alonso set the eighth and ninth fastest times behind the two Force India drivers.
Where to watch live
Free Practice 3 will begin at 4pm BST (Saturday), while the qualifying session for the United States Grand Prix will begin at 7pm BST. Sky Sports F1 and Sky Sports F1 HD will provide live coverage of both events in the UK. Real-time internet updates are available on the Live Timing section of the sport's official website.
Top ten drivers after FP2 at the Circuit of the Americas: