Ahead of today's second session the air temperature is 26 degrees C, while the track temperature is 44 degrees.

Having handed over their cars to their teams' respective rookies, juniors and reserves earlier, no less than nine drivers are back in their regular seats this afternoon.

They are Norris at McLaren, Hamilton at Ferrari, Russell at Mercedes, Verstappen at Red Bull, Stroll at Aston Martin, Gasly at Alpine, Bearman at Haas, Sainz at Williams and finally Lawson at RB.

In terms of updates, Ferrari has new Cooling Louvres and a new Rear Corner. Both are specific to the requirements of the circuit, with the new bodywork exit louvres extending the top end of the engine cooling capacity, at the expense of car efficiency. As for the engine cooling options, this update targets an increased cooling capacity for the rear brakes to cope with the requirements of the track.

In its quest to help Max Verstappen win the title, Red Bull has brought a new Front Corner, Engine Cover, Floor Body and Edge Wing. Given the rigours of brake cooling in the reduced atmospheric pressure of Mexico City, larger inlet and exit caps have been prepared for this race to simply recover air mass flow. As for the engine cover, in work carried out for the previous cooling revision, more benefit was found from redistributing the exit air and given scope to introduce via an update to existing tooling, this can be deployed in Mexico. In addition, a wider louvre exit panel is available to recover mass flow in the ambient conditions encountered. As a make from the previous specification of floor, a new upper surface rearwards of the outer floor fence plus sidepod split line are offered, the latter to accommodate the sidepod revision. These offer the cooling benefit noted above a small increase in load. Finally, to draw benefit from the lowered upper floor surface and made from the previous edge wing specification, a revised leading edge region extracts a little more load whilst maintaining flow stability.

Alpine has a new Coke/Engine Cover. As a consequence of the high cooling demand of the track, the bodywork exit has been updated to increase the air flow through the coolers.

Racing Bulls have a new Coke/Engine Cover and Cooling Louvres. The main cooling exit at the rear of the bodywork has been enlarged, to increase the available engine cooling, while the louvre panels used at circuits with high engine cooling requirements have been made larger to increase engine cooling.

Williams also has new Cooling Louvres. The increased number/size of the louvres increases the flow of air through the cooling system, which helps compensate for the relatively low air density in Mexico City. The higher cooling panels have a negative effect on downforce and drag and therefore will only be used if necessary to cool the PU in the ambient conditions of this weekend.

New Cooling Louvres for Sauber also due to the increased mass flow rate required for the particular ambient conditions here. This update provides a higher maximum cooling level.

Leclerc was quickest in FP1, ahead of Antonelli, Hulkenberg, Piastri, Bortoleto and Lindblad, the youngster greatly impressing.

With the young drivers sorted we can now get down to the serious business of preparing for tomorrow afternoon and Sunday.

A major technical issue earlier not only affected the always unreliable live timing app but also on-board cameras and even GPS, which meant a nightmare for those on the pit wall especially as they tried to warn the rookies about traffic and drivers on flying lap. In short it was a bit of a cluster**** and one has to hope that it has been resolved.

Track evolution is highly noticeable here, and consequently - rookies aside - the early sessions - FP1 and FP3 - are somewhat unrepresentative, much those at the night races.

Consequently, this session should give us a better idea of the pecking order for qualifying and the race.

Lawson is first out, followed by Russell, Bearman, Sainz and Stroll, all having missed the earlier session.

"I've got an issue," reports Antonelli.

As more drivers emerge all three compounds are in use, Alonso on softs.

Russell posts a benchmark 20.253, as Antonelli is told to continue despite his concern.

Indeed, the Italian goes top with a 19.444, only to be leapfrogged by Leclerc (18.669). both are on mediums.

Offs for Stroll, Russell and Hamilton as Albon goes second with a 19.306.

"I've got a lot of misfires," reports Norris. "Every corner, a lot of surges."

Piastri goes third and Russell seventh.

A 19.044 puts Verstappen fourth. However, the Dutchman is demoted when Hamilton goes third with an 18.689.

Alonso (mediums) goes seventh with a 19.226, just ahead of his teammate who is now on softs.

Leclerc improves with an 18.353 as mechanics swarm over Antonelli's car in the Mercedes garage.

The dusty track surface continues to catch the drivers out, the latest being Norris.

Whatever Antonelli's issues was appears to have been fixed for he is heading out again.

With 40 minutes remaining, Bortoleto and Albon switch to softs.

Albon brushes the wall with his left-rear in the penultimate corner but is able to continue.

More and more drivers switch to the red-banded rubber. Among them is Leclerc who immediately goes purple in S1. He crosses the line at 17.545 around 0.8s up on his previous best.

Colapinto goes fifth with an 18.721, while Piastri crosses the line at 18.232 to go second.

An 18.180 from Norris but Sainz posts a 17.939 and Russell a 17.829.

Hadjar goes sixth and Hulkenberg seventh, as Verstappen goes quickest in S2. The Dutchman crosses the line at 17.392, 0.153s up on Leclerc and 0.7s up on the McLarens.

Tsunoda goes fourth and Alonso fifth.

Sainz goes sixth with a 17.939, as Antonelli improves to third (17.566) and Hamilton fifth (17.692).

Content with his time, Verstappen switches back to the mediums, Leclerc following suit.

While more drivers switch to the yellow-banded rubber, the McLaren pair stick with softs.

"It's terrible, I have no grip," complains Verstappen as her has a huge slide, "it's like driving on ice."

"Rears are terrible on this medium," agrees Russell.

The long runs continue, most on mediums though the McLarens are on softs, as are Stroll, Lawson, Hulkenberg, Bearman and Colapinto. Norris is slightly quicker than his teammate.

The rear of Leclerc's Ferrari gets extremely loose in Turn 2 but he holds it all together.

Antonelli locks-up in Turn 13 after encountering a slow Lawson.

Verstappen switches back to the softs, as does Russell. Remember, both were unhappy with their mediums.

Leclerc gets a tow from Russell and looks as though he's going to make the pass, but doesn't.

Indeed, there are a few little battles, Stroll and Gasly and Hamilton and Hulkenberg.

Norris and Piastri have reverted to mediums.

The session ends. Verstappen is quickest, ahead of Leclerc, Antonelli, Norris, Hamilton, Russell, Tsunoda, Alonso, Sainz and Stroll.

Lawson is eleventh, ahead of Piastri, Ocon, Hadjar, Bortoleto, Hulkenberg, Bearman, Colapinto, Albon and Gasly.

An interesting session, and while Verstappen wasn't happy with the mediums, that gap to the McLarens, especially Piastri, is sure to have the Woking team burning the midnight oil.

Ferrari is looking good but as Fred Vasseur said earlier the team's fortunes seem to change from day to day.

Mercedes also look strong, as do Aston Martin.