Max Verstappen led Daniel Ricciardo in a Red Bull one-two in the final practice session but the Mercedes drivers clearly had more pace in hand.
Daniel Ricciardo was not getting carried away by his performance after lapping within two tenths of a second of the Mercedes drivers on Friday in Austin.
Nico Rosberg took over from Lewis Hamilton on the top of the times sheets in Austin – and the Mercedes pair were separated by a Red Bull.
Pictures from the first day of practice for the 2016 United States Grand Prix.
The Mercedes drivers occupied their customary position at the top of the times sheets in first practice for the United States Grand Prix, but with an inflated margin over their rivals.
Pictures from the build-up to the 2016 United States Grand Prix.
Nico Rosberg cannot clinch the championship in the USA, as Lewis Hamilton did here last year, but he could make it a foregone conclusion
Fans who braved the dreadful weather at last year’s United States Grand Prix will be well rewarded if they return for this year’s race, which should be dry and warm.
The Circuit of the Americas, which is hosting the United States Grand Prix for the fifth time this year, is as good as it gets in terms of modern track layouts.
Don’t miss any of the 2016 United States Grand Prix sessions – here are the times for all of this weekend’s action.