Formula 1 got a cold, crisp welcome in Austin for Friday practice at the United States Grand Prix.

The day began with a bit of a shock for the drivers, literally, as the harshness of the bumps around the Circuit of the Americas proved quite a challenge for the cars.

Once that was overcome, the focus switched to tyres as Pirelli provided a 2020-spec developmental soft compound to use and plenty of running ensued as teams tried to gain crucial data not only on its performance but also how it impacted the airflow over the cars.

There were some setbacks, notably Nicholas Latifi grinding to a halt in the Williams to a gearbox issue and Nico Hulkenberg also been briefly sidelined by a hydraulics problem.

Carlos Sainz also lost a set of tyres after a high-speed spin in the Esses before continuing.

Throughout the morning session though, the pace was set by Red Bull as Max Verstappen and Alex Albon traded fastest times, despite also having some laps deleted as the stewards cracked down on track limits at Turn 19.

Eventually, it would be the Dutchman on top as Max posted a 1m34.057s on the 2019-spec soft rubber to lead Sebastian Vettel by two-tenths of a second.

Mercedes' decision to focus predominantly on 2020 tyre work meant Lewis Hamilton ended the session in eighth, while Valtteri Bottas was a lowly 17th.

Charles Leclerc also reported engine issues early, which were later linked to the throttle system, and the Monegasque was only seventh fastest as he too focused on the developmental rubber.

That allowed Pierre Gasly to sit in fourth place for Toro Rosso, just ahead of Daniel Ricciardo in the Renault as the two teams battling for fifth in the Constructors' standings went head-to-head.

Haas also created some initial optimism at their home race with both cars in the top 10 but that would change in the afternoon.

Romain Grosjean caused a red flag early in second practice, swiping the front of his car against the barrier in the Esses section.

And mistakes were a theme of the session as Antonio Giovinazzi, Vettel and Daniil Kvyat all spun at different areas around the technical COTA layout.

As the serious work of qualifying and race simulations got underway though, it would be Mercedes who jumped to the top through Hamilton with a rapid 1m33.232s.

That time could be deceiving though as the Briton got a strong slipstream on the back straight during his lap, potentially accounting for more than the three-tenths advantage he had over Leclerc and Verstappen.

Despite his spin almost in the same place as on Lap 1 a year ago, Vettel would sit fourth in the second Ferrari ahead of Bottas in fifth, as his already slim chances of keeping the championship alive appear even smaller.

Four different midfield teams featured in the four places from P7-10, with Gasly again leading the charge and within the same tenth of Alex Albon in the Red Bull.

McLaren had a tricky day but Sainz still showed the inherent pace of the British team in eighth with Lance Stroll and Antonio Giovinazzi completing the top 10.

Perhaps the most frustrated team will be Renault as Ricciardo sat 11th with Nico Hulkenberg 13th, albeit separated by tiny margins as 0.6s covered P7-P15.

At the back of that group was Sergio Perez but the Mexican already faces a pit-lane start after repeating the mistake Pierre Gasly made in Baku by missing the weighbridge on entering the pits, resulting in the severe punishment.

Last year's winner in Austin, Kimi Raikkonen, was 16th, as the two Haas' and two Williams' rounded out the field, with George Russell 0.5s clear of teammate Robert Kubica.

With tight battles up and down the grid, an action-packed weekend appears on the cards in the US, providing the bumps, which left many drivers unhappy, don't get much worse.