Ahead of today's first free practice session the air temperature is 21 degrees C, while the track temperature is 28 degrees. It is bright and sunny.

All eyes on Lewis Hamilton and Mercedes this weekend following last week's big end bearing failure, which has resulted in the German manufacturer revising the running parameters of all its engines both works team and customers.

Hamilton reverts to his Singapore unit while his teammate continues with the unit he used to finish third at Sepang.

New units without penalty for Raikkonen, Kvyat and Magnussen.

Red Bull was already sensing the opportunity of taking another win and the news that Mercedes has to effectively turn the wick down will give the Austrian team even more hope.

Ferrari, and in particular Sebastian Vettel, who strongly denies that he is over driving, is also looking for a strong weekend.

Meanwhile, the titanic battle for fourth, featuring Force India and Williams, continues.

The lights go green and Grosjean leads the way, the Frenchman having admitted that he is trying to tone down his radio rants.

He is followed by Ocon, Gutierrez, Palmer, Magnussen and Vettel on to a track where the cars can really stretch their legs.

Tyres are the same as last week, hard, medium and soft, all three currently being used.

In just four minutes all but Verstappen have appeared... though the Red Bull driver subsequently obliges. Teammate Ricciardo's car sported the sensors we normally see in testing.

Following that initial brief burst of activity, there follows a brief lull with Kvyat, and then Perez, the only drivers on track.

Perez posts the first time of the weekend, the Mexican crossing the line at 1:34.956 on softs.

As Wehrlein (medium) posts 39.458, more and more drivers head out.

Grosjean posts 37.420 but is instantly demoted when Alonso crosses the line at 36.178. The Spaniard is using the latest Honda unit this weekend, the version trialled last Friday and for which the McLaren driver received his penalties.

A big spin for Alonso at T14, the McLaren spinning wildly across the run off and then the grass as the rear stepped out. Losing an endplate he is lucky not to incur more damage as the rear of the car hit the advertising hoarding quite hard.

Shortly after, Raikkonen runs wide in the hairpin. Nonetheless, next time around he posts 34.746 to go quickest.

Hulkenberg goes third, ahead of Verstappen, Alonso, Grosjean, Nasr and Button.

It's business as usual as Rosberg goes quickest (33.751) leapfrogging Hamilton who had just posted 33.967, both, like Raikkonen, on the softs.

Asked to tell his team about the upshifts, Verstappen replies "they're bad". "Can we have a bit more information," comes the response, "we need a bit more than that."

"I'm very low on power," says Hamilton.

A 34.334 sees Vettel (softs) go third, 0.583s down on Rosberg.

The Red Bull duo are currently seventh (Ricciardo) and eighth, both over 1.5s off the pace, both on hard.

Perez is back on track, now sporting a Halo device.

In the McLaren garage lots of work going on on Alonso's car.

"The right-hand side mirror has gone again," complains Hulkenberg. "I don't see anything there." Elsewhere, countryman Rosberg complains of "monster understeer". (Groan)

Clearly, young Verstappen could learn from Vettel who gives some excellent feedback to his team.

At which point, Verstappen advises: "Downshifts are like a handbrake".

Forty minutes in, and as the driver hand back their extra set of tyres, it's: Rosberg, Hamilton, Vettel, Raikkonen, Perez, Hulkenberg, Ricciardo, Verstappen, Alonso and Button... perfect symmetry.

The track falls silent. Indeed, it's surprisingly long lull, with most drivers climbing from their cars. Vettel is involved in deep conversation with a team member, his helmet perched precariously on his head.

Check out our Friday gallery from Suzuka, here.