If the update is Ferrari's biggest of the year, it looks to be working for Charles Leclerc. The Monegasque driver pulls out more performance from his car to jump above Max Verstappen's Red Bull by 0.084 seconds. The new time to beat is 1:36.052.

McLaren's Oscar Piastri goes seventh quickest, as Kimi Antonelli in fifth is finding it difficult to keep his Mercedes under control towards the end of the lap.

Rebecca Clancy
F1 journalist on BBC Radio 5 Sports Extra in Austin

The chat in the paddock this morning is that the upgrades that Ferrari have brought are actually far more significant than the drivers have been letting on. Some are even suggesting that it's the biggest upgrade package of the year for Ferrari.

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The drone shot is back for the TV coverage this weekend. It's following Max Verstappen, who is purple in the first sector and has enough pace in the bank to beat Charles Leclerc's top time by 0.192 seconds.

Red Bull team-mate Isack Hadjar has moved up the order on his flying lap on the soft compound, slotting into fifth place with a 1:36.490.

Kimi Antonelli needs to win this weekend and George Russell and Lewis Hamilton to trip up in order to become the youngest ever F1 world champion. The 20-year-old is more than four tenths off Charles Leclerc's best time at the moment, sandwiched between Lando Norris, who was fast in the middle sector, and seven-time world champion Lewis Hamilton.

Charles Leclerc is a past winner in Austin and the Ferrari man is looking quick already. He's switched onto the soft tyre now and his new lap time of 1:36.052 is good enough to keep him at the top of the timesheets.

Max Verstappen is second quickest, 0.084 seconds off the pace of the Monegasque driver on the same soft compound.

The Williams garage is busy on both sides as Carlos Sainz and team-mate Alex Albon wait to set an opening lap time in first practice in Austin. It's been a disappointing season overall for the team, and they sit ninth in the constructors' championship behind the likes of Audi and Haas.

Speaking of Audi, German Nico Hulkenberg says his car has "very weird behaviour in the last corner," at COTA.

1. Charles Leclerc (Ferrari) - 1:36.761

2. Lewis Hamilton (Ferrari) +0.074

3. Lando Norris (McLaren) +0.423

4. Kimi Antonelli (Mercedes) +0.424

5. George Russell (Mercedes) +0.493

Image source, Getty Images

Even Formula 1 drivers get put on the naughty step when they misbehave on track.

Reigning world champion Lando Norris said he had "plenty of telling offs" after his contact with McLaren team-mate Oscar Piastri on the final lap of the sprint event in Singapore last time out. Norris came away with a single point while Australian Piastri was left with a DNF in the shorter race.

After the dressing down, Norris added the pair are still free to race each other over the remaining races, they just can't do anything stupid.

Norris has dropped to sixth in the drivers' championship after his back-to-back victories in Hungary and Zandvoort following the summer break, and in Austin, he's third on the timing screen, four tenths behind leader Charles Leclerc.

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The drivers could be in for a bumpy ride around the Circuit of the Americas this weekend.

Four-time world champion Max Verstappen said on Thursday he loves this track and the layout, and he also loves being in Austin, however, the rough nature of the circuit leaves a lot to be desired.

"For me the bumps are unacceptable. Over time they've been grinding a little bit here and there but it's just putting a plaster on the big problem," said the Dutchman.

"But that of course means you need to really fully open up the track. That costs a lot of money and time but that's the only way to get rid of it because these bumps are not natural and they are out of control."

Lumps and bumps aside, Verstappen is aiming for a third consecutive victory on Sunday following his wins in Singapore and the Bahrain Grand Prix in Malaysia. He;s also made the podium in the past five grands prix, too.

Ferrari have brought some upgrades to the United States Grand Prix as they look to celebrate a first win since Charles Leclerc's victory at Silverstone in the summer.

The Italian team are one and two on the timesheets so far, but it's now Leclerc who is quicker than team-mate Lewis Hamilton by 0.074 seconds on the same medium tyre.

Over at Mercedes, George Russell is telling his pit wall to check the front wing, saying he is experiencing "lots of understeer".

Lewis Hamilton was in reflective mood on Thursday, going over how his strategy error in Singapore cost himself and Ferrari a podium finish at Marina Bay. The seven-time world champion said it was a "split-second decision" to stay out and not pit under the virtual safety car, adding he held his hands up to the team and took responsibility for it.

Can he get back on the podium this weekend? Ferrari have been backed to perform well at COTA, and Hamilton has just put himself top of the timesheets with a 1:36.835 on the medium compound.

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If the steering feels weird, it hasn't affected Max Verstappen's ability to clock a quick lap just yet. The Dutchman jumps to the top of the timesheets with a 1:38.040 but that marker is beaten by the Ferrari of Charles Leclerc.

The Monegasque driver, who is about to become a dad any day now, is eight tenths faster than the Red Bull with a 1:37.430. World champion Lando Norris is next to cross the line and goes within six tenths of Leclerc to slot into second place.

Harry Benjamin
BBC F1 Commentator in Austin

Turn One is so wide, it gets wider as you up the corner and then it pincers you in right at the apex. You can take multiple lines through that corner - it's a prime overtaking spot straight away.

American Colton Herta is in for Sergio Perez over at Cadillac in this first practice session, the only rookie out on track at the moment.

There is a mix of medium and hard tyres on show in the opening stages of this session - and some hefty aero rakes - with Lando Norris quickest so far with a time of 1:38.715.

At Red Bull, Max Verstappen is chatting to his new engineer Tom Hart, who is taking over the radio from Gianpiero Lambiase this weekend. "Steering feels weird, steering left, there is some sort of friction," says the four-time world champion.

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Lewis Hamilton drew laughs in the news conference yesterday when he was asked if he had any advice for Kimi Antonelli. "Slow down!" said the seven-time world champion.

Ferrari's Hamiton then went on to praise the young Italian, adding his performances have been "massively impressive".

Rosanna Tennant
5 Live F1 reporter in Austin

It might only be Friday, it might only be FP1, but the hill is packed out with fans.

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George Russell fully embraced his inner cowboy today as he made his way into the paddock. I think he pulls the look off - what do you reckon?

Yeehaw. First practice is green.

BBC Sounds

A big Texan hello to Harry Benjamin, Williams reserve driver Luke Browning and BBC F1 correspondent Andrew Benson for Friday's practice running.

To tune in, you can either click the listen live tab at the top of the page, search for 5 Sports Extra on the BBC Sounds app if you're heading out tonight or you can ask your smart speaker to "play 5 Sports Extra".

More insight and analysis will be available on the F1: Chequered Flag podcast today - just search 'F1' on BBC Sounds.

Pirelli has selected the C2 as the hard, C3 as the medium and the C4 as the soft tyre for this weekend's United States Grand Prix.

A section of the 5.513km Hermann Tilke-designed circuit between Turns Nine and 11 was resurfaced earlier this year, but high tyre wear could still play a key role over the three days of track action. The 56-lap grand prix is likely to be a one-stop on Sunday, so the C2 hard compound could favour long stints.

There are two straight mode zones in Austin, one between Turns 11 and 12 and the other along the start-finish straight after the final corner at Turn 20 and into Turn One.

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Kimi Antonelli has cut a relaxed figure in the paddock so far but the hard work on the road to getting his hands on the 2026 title starts today.

The Italian isn't letting the pressure get to him, though, and he intends to keep the weekend as light-hearted as possible.

"It's crazy if you think about it, but that's why I won't think about it," Antonelli said on his chances of lifting the championship as early as Austin.

"Something catastrophic to others needs to happen for me to become (champion). For me, needs to be a perfect weekend and to the others they need to do a poor result, which is unlikely to happen.

"Everything, anything can happen. But as I said, you know, we had a meeting with 'Bono' (race engineer Peter Bonnington) this morning and we just said: 'Just have fun.' Just always the same mindset as I had all year, one race at a time."