Some tyre chat for you - Pirelli have brought the soft and medium compound to Austin, compared to the medium and hard choices from the previous two races. Why? Well I expect its because those grands prix saw mostly just one stop per driver. The latest selection should force more stops.

Image source, Mercedes/Twitter

Mercedes on Twitter:, external In the zone...

Image source, Getty Images

The pit-lane doors have swung open. In the words of Lewis Hamilton's race engineer: "It's Hammer Time!"

BBC Radio 5 live sports extra

We've got live commentary on BBC Radio 5 live sports extra. All you have to do is click the audio speaker in the top left of this page. If you missed last night's preview show, you can listen again here.

David Wiles:, external I do think F1 teams should be able to make a living out competing, at least as much as shareholders.

Jennie Gow
BBC Radio 5 live pit-lane reporter

"Sebastian Vettel will be sporting a Captain America helmet."

Andrew Benson
Chief F1 writer

"Keep an eye out for a novelty at Lotus, who are trialling a new low nose in first practice. The idea is to gather data ahead of 2015, when the loophole that led to the 'anteater' noses on many of the cars this year has been closed, forcing all down the route chosen this year by Ferrari and Mercedes.

"Pastor Maldonado said it would only be used for one run in first practice to correlate the information from the track with that from the wind tunnel. Would he be using it? He said he didn't know.

"After his crash-strewn year, perhaps it would be better if it was left to team-mate Romain Grosjean, who has announced ahead of this weekend that his wife is expecting their second child. 'At least that worked,' he joked, in a reference to Lotus's dreadful season."

Image source, Lotus F1/Twitter

Lotus F1 on Twitter:, external Special lid for Romain Grosjean this weekend, who is a fan of Matt LeBlanc?!

Image source, Red Bull on Twitter

I tip my hat to Daniel Ricciardo for his Texan style facial hair this weekend. Incredible scenes.

Joining Max Verstappen in this first practice run-out is Felipe Nasr, who is borrowing Valtteri Bottas' Williams for 90-minutes.

Andrew Benson
Chief F1 writer

"Max Verstappen's crash-course in F1 continues this weekend. The 17-year-old Dutchman, who will race for Toro Rosso next year, gets another go in first practice following on from his first taste in Japan two races ago. He judged his first effort 'not too bad' - which was a fair comment for being a few 10ths of a second off Daniil Kvyat. His progress will be watched with interest."

Image source, Max Verstappen on Twitter

And over in Austin, Max Verstappen, who will make his F1 debut next season with Toro Rosso, had a go at indoor skydiving.

Image source, Ferrari on Twitter

While Lewis Hamilton was in New York, Kimi Raikkonen headed to Louisville, Kentucky to take the controls of a Boeing 757 aircraft, albeit in a simulator, in the build-up to this weekend's race.

The downside was he had to help in the freight sorting office afterwards...

Image source, Ferrari on Twitter

Rain hit Austin earlier today, but conditions are somewhat brighter now and with the sun bursting through, the track is drying ahead of the start of the session.

Andrew Benson
Chief F1 writer

"Some housekeeping before we get going. The weekend is only just getting under way, but already there are likely to be two grid penalties. Jenson Button says he will have a five-place grid penalty for a gearbox change in his McLaren, and breaking the rule that requires drivers to use the same gearbox for six races. Sebastian Vettel, meanwhile, looks certain to miss qualifying altogether and start from the back of the grid for taking a sixth all-new engine with all its elements.

"This is not completely confirmed, but it has been heavily trailed by Red Bull ahead of the weekend. 'As far as I know the plan is to pull a sixth component of all the components,' Vettel said, 'and if you do that you have to start from the pit lane. So our plan could be a little different in terms of how we approach practice and qualifying. You try to prepare for the race. Practice largely we will try to focus on the race because whatever you do in qualifying you start from the back anyway.'"

Image source, Lewis Hamilton on Twitter

There was also a good turnout for Lewis Hamilton, when he turned up in New York with his Mercedes W05 for his appearance on NBC's Today Show on Wednesday.

Image source, Getty Images

Sebastian Vettel caused a scene in downtown Austin when he took his Red Bull out for a spin along North Congress Avenue, backdropped by the Texas Capitol building. It seemed to go down a storm, with the place packed with fans.

There's a few talking points to get stuck into today. So don't be shy. Have your say.

Do you think Formula 1 needs a cost cap or is the fact that teams come and go - over 150 have competed in the sport during its 50 year history and only nine are still going - just part of the sport?

Sebastian Vettel, the reigning world champion, might skip qualifying, because he has to use a sixth power unit of the season, one more than is allowed, which means even if he qualifies on pole, he will have to start in the pit-lane? What do you think of these engine rules?

And the Circuit of the Americas is the 10th different F1 venue in the USA - how does it rate against the other nine?

Tweet us using #bbcf1, external hashtag, text 81111 (UK only) or leave a comment on the BBC Sport Facebook page., external

Today, it's all about practice - with two 90-minute sessions providing teams and drivers with an opportunity to gather data for qualifying and the race. The first session kicks off at 16:00 GMT, the second follows at 20:00.

Andrew Benson
Chief F1 writer

"In just three years, the US Grand Prix in Austin, Texas, has become a real highlight of the Formula 1 season, up there with the likes of Melbourne, Monaco, Montreal, Spa and Monza as one of the must-visit events. Austin, like very few places on the calendar, has everything, from a good circuit to an atmospheric location in a buzzy, happening city packed with bars hosting live music.

"As Red Bull's Daniel Ricciardo explains: 'It's definitely one of the better - if not the best - modern generation circuits. You can pass, the wide corner entrances create more opportunities for overtaking. I honestly think it's the best circuit on the calendar for overtaking. I think there are more spots around the lap here for overtaking opportunities than any other, so that's always exciting. And Austin is fun, cool. I love my music and I could sit in those bars all night watching people doing their thing.'"