Lewis Hamilton set the pace ahead of Nico Rosberg as just 18 cars put in the laps in Friday’s practice for the United States Grand Prix.
With neither Caterham nor Marussia in action this weekend after both teams went into administration, the US GP weekend got underway with the smallest field since 2005.
After a spot of rain very early in the morning washed the track clean, the sun baked down on the Austin circuit in preparation for FP1.
The session began with a Mercedes 1-2 as Hamilton and Rosberg were quickly into the action. And, as many expected, it ended in the same manner.
Championship leader Hamilton, who is chasing his fifth win in succession this weekend, set the pace with a 1:39.941 while Rosberg was 0.292s slower than his team-mate.
Jenson Button finished third quickest having held onto the P1 slot throughout the middle stage of the 90-minute session.
The Brit racer had been in charge of a McLaren 1-2 for a good 30 minutes but as the drivers dialled in to the track the timesheets changed.
While Button dropped to third, Kevin Magnussen was fifth with the McLaren drivers split by Daniil Kvyat. The STR rookie was the last driver to get within a second of Hamilton’s P1 time.
Fernando Alonso, who trialed a new front wing for Ferrari, was sixth quickest ahead of Sebastian Vettel and Felipe Nasr.
The Brazilian was one of two test drivers in action on Friday as Max Verstappen was put in the laps for Toro Rosso. He finished P10, 1.844s off the pace.
Meanwhile, it was a trying start to the weekend for Daniel Ricciardo as an ERS problem meant he completed just five laps and finished 17th quickest out of 18 drivers.
Romain Grosjean, who put Lotus’ 2015 box nose design through its paces, completed the timesheets.
In the minutes after the session, the drivers took to the track to trial a ‘virtual safety car’ as they lapped to a pre-set time decided by the FIA. This was a test in response to Jules Bianchi’s Japanese GP crash.
01 Lewis Hamilton Mercedes 1:39.941 28 laps
02 Nico Rosberg Mercedes 1:40.233 +0.292 32 laps
03 Jenson Button McLaren 1:40.319 +0.378 27 laps
04 Daniil Kvyat Toro Rosso 1:40.887 +0.946 33 laps
05 Kevin Magnussen McLaren 1:40.987 +1.046 29 laps
06 Fernando Alonso Ferrari 1:41.065 +1.124 27 laps
07 Sebastian Vettel Red Bull 1:41.463 +1.522 20 laps
08 Felipe Nasr Williams 1:41.545 +1.604 19 laps
09 Nico Hulkenberg Force India 1:41.722 +1.781 24 laps
10 Max Verstappen Toro Rosso 1:41.785 +1.844 32 laps
11 Felipe Massa Williams 1:41.907 +1.966 21 laps
12 Kimi Raikkonen Ferrari 1:41.965 +2.024 23 laps
13 Pastor Maldonado Lotus 1:42.329 +2.388 28 laps
14 Adrian Sutil Sauber 1:42.333 +2.392 23 laps
15 Sergio Perez Force India 1:42.359 +2.418 23 laps
16 Esteban Gutierrez Sauber 1:42.516 +2.575 24 laps
17 Daniel Ricciardo Red Bull 1:42.598 +2.657 5 laps
18 Romain Grosjean Lotus 1:43.229 +3.288 26 laps