Ahead of today's opening session, the air temperature is 28 degrees C, whilst the track temperature is 35 degrees.

The big news today isn't about this weekend's race, rather 2016 and Christian Horner's revelation that Red Bull has secured an engine deal. However, he was unable (unwilling?) to say whose.

The other drama is in the Lotus garage where the team looks likely to be able to field only one car this morning.

As previously reported, due to "issues" the Enstone outfit's equipment arrived only yesterday, leaving the crew with a monumental job. Officials allowed the team to delay scrutineering until this morning and whilst Maldonado's car is ready to go, the other, which would have been driven by Jolyon Palmer, is unlikely to run, the Enstone outfit citing an "ill-timed water leak".

This being another 'twilight zone' event, this is the only session which takes place in daylight. Consequently, like other such events, this morning's session will have little in common with the remainder of the weekend. Indeed, the teams are likely to use the next ninety minutes as a glorified test session as they focus on 2016.

The lights go green and Kvyat leads the way, followed by Vettel, Ricciardo, Merhi and Verstappen.

As more and more cars head out, many are sporting the massive gate-like sensors and various other devices, confirming that the session will be primarily used for testing. There is a test here next week (Tuesday) but it is strictly limited to tyre testing, with no aero testing allowed. Consequently...

A close-up of Raikkonen's car reveals lights (lasers?) underneath the rear of the Ferrari on both sides.

After ten minutes we've yet to see any times. While most drivers complete a sole installation lap others dive into the pitlane and then continue.

Hamilton queries the positioning of his seat, claiming that it is higher than usual. The team denies this.

Finally, Rosberg posts a time, the German stopping the clock at 1:55.130. He subsequently improves to a far more sensible 44.626.

Hamilton posts 50.485, only to be demoted when Verstappen bangs in a 48.412 moments later.

As Rosberg, despite a "long" brake pedal, posts 44.102, going quickest in all three sectors, Vettel runs wide and subsequently heads to the pits.

Twenty minutes in and all but Kvyat, Vettel, Ricciardo, Nasr, Alonso and Palmer have posted times.

A 43.996 sees Hamilton go quickest, as Perez goes third, ahead of Hulkenberg, Raikkonen, Bottas, Massa and Button.

Rosberg re-takes the top spot with a 43.895 as Hulkenberg leapfrogs his force India teammate.

Raikkonen improves to third (45.206), the Finn just one point behind countryman Bottas in the championship.

The opening half-hour comes to an end and as the drivers hand back their 'free' set of tyres, it's: Rosberg, Hamilton, Raikkonen, Hulkenberg, Perez, Maldonado, Bottas, Verstappen, Massa and Button.

Kvyat, Vettel, Ricciardo, Nasr, Alonso and Palmer have yet to post times though all, bar the Briton, have been out.

There follows the traditional 'lull'.

After around eight minutes of total inactivity - at least on track - Alonso fires up his Honda and heads down the pitlane. In a number of garages there is plenty of activity as the mechanics work on the cars.

More drivers head out, among them Button who says he is "losing the rears very quickly".

Hamilton is told that his previous stop was "ten centimetres long, twenty to the left". They should see some of the parking at our local Sainsbury's.

As Rosberg runs wide in T1, subsequently complaining about brake issues, Alonso improves to eighth with a 46.181.

Though we won't see them in this session, Pirelli reveals: "The supersoft tyres are used here because the surface is smooth and there are more low-speed corners than high-speed corners".

As the camera picks up on Ricciardo taking a pounding as he rides the kerbs, former teammate Vettel heads down the pitlane having laid a thick layer of rubber outside his garage.

On his first flying lap Vettel goes eighth (45.922), leaving Nasr and Palmer as the only drivers still to post a time.