Ahead of today's opening practice session the air temperature is 18 degrees C, while the track temperature is 43 degrees.

In terms of updates, Red Bull has a new Coke/Engine Cover and Front Corner, both being circuit specific to aid with cooling. Ferrari has new Cooling Louvres. Specific to the requirements of the circuit, these new bodywork exit louvres are extending the top end of the engine cooling capacity, at the expense of car efficiency.

McLaren has a new Coke/Engine Cover, Cooling Louvres and Floor Body, the last of which has been heavily revised, with geometric changes in all areas, resulting in an increase of aerodynamic load across all conditions.

Williams has a new Beam Wing and Coke/Engine Cover, again circuit specific. The engine cover to cover the increased PU cooling requirements that result from the altitude, a larger bodywork exit is available to increase the air flow through the coolers.

RB has new Floor Fences, Floor Edge, Coke/Engine Cover and Cooling Louvres. The revised floor fences improve the quality of the vortex formation on the fences, reducing the aerodynamic losses downstream.

While Mercedes, Aston Martin, Alpine, Stake and Haas do not have any upgrades, Lewis Hamilton is running the Austin upgrade while George Russel retains the old spec until the floor damaged last weekend has been repaired, hopefully in time for Brazil.

"As I was the one damaging the upgrade at Austin, Lewis got the choice and elected to take the new one this weekend," confirmed Russell.

There are a number of young drivers on duty this morning, Antonelli at Mercedes, Drugovich at Aston Martin, Bearman at Ferrari, Schwartzman at Stake and O'Ward at McLaren. They are replacing Hamilton, Alonso, Leclerc, Zhou and Norris respectively.

With FP2 set aside for tyre testing this session is crucial not just for the weekend but in terms of testing the various upgrades.

The lights go green and Drugovich leads the way, followed by Bearman, Tsunoda, Schwartzman and Gasly. As more drivers head out hards are very much the order of the day.

"Steering is slightly bent," reports Gasly. "It's quite bad." He subsequently pits.

Just moments into the session it is red-flagged due to debris on the main straight.

Verstappen had just gone quickest (20.970), ahead of Bottas, Piastri, Ocon and O'Ward.

The session resumes with 49 minutes remaining, and judging by the activity in the Red Bull garage that debris might have come from Verstappen's car.

Magnussen goes top with a 20.912, and as Sainz goes second to the Haas driver Perez bangs in a 20.795 and Russell a 20.727.

As is always the case here, the entrance to the stadium sees a traffic jam slowly build.

Sainz improves with a 19.942 only to be demoted by Russell's 19.816.

Tsunoda goes fourth, but drops to fifth when Albon stops the clock at 19.812.

"Smells like something's cooking in the car," reports Gasly. Mmmm tacos!

A second red flag with 37minutee remaining following what appears to be an incident involving Albon and Bearman.

Replay shows Albon suffering a snap of understeer as he was passing Bearman, and hitting the Ferrari as the youngster slowed to let him through.

"Idiot!" declares Albon.

"He hit me, I'm out," declares Bearman. "I'm fine but the car is damaged," he adds.

The incident will be investigated after the session, as will Drugovich for overtaking under yellow flags.

The session resumes with 22 minutes remaining, and now it's mainly the red-banded rubber that is in use.

Verstappen is already racing Sainz, the Spaniard using DRS in an attempt to shake off the Dutchman as they approach the stadium.

Russell posts a 17.998 as Hulkenberg goes fourth and Piastri fifth.

Piastri is told he's losing out everywhere, especially traction in the final corner.

Bottas goes sixth, Gasly tenth and Ocon eleventh.

"It feels pretty terrible still," reports Piastri, when asked if he want to do more continuous laps.

O'Ward improves to eleventh on his first flaying lap on softs. He is subsequently demoted by Lawson and then Antonelli.

Satisfied with his work - he's 0.317s up on the closest opposition (Sainz) - Russell switches back to the hards.

Tsunoda goes third with an 18.699 as Antonelli begins his first flying lap on softs.

"There's something wrong with the engine, mate," reports Verstappen. "I have no power."

He somehow makes the word "mate" sound threatening.

Antonelli aborts his flyer.

Piastri runs wide in Turn 12, the Australian clearly struggling as McLaren continues to suffer a balance issue as it did in Austin.

Drugovich is hampered by traffic and fails to improve on his flying lap. "I'm still way too far from the limit," says the Brazilian, "but it was good, thanks guys."

The session ends, Russell is quickest, ahead of Sainz, Tsunoda, Verstappen, Hulkenberg, Piastri, Ocon, Bottas, Lawson and Perez.

Colapinto is eleventh, ahead of Antonelli, O'Ward, Magnussen, Gasly, Stroll, Albon, Drugovich, Schwartzman and Bearman.