So we're seven minutes or so away from FP2.

All the regular drivers are back in the cars, so that means Kevin Magnussen returns for Haas and Carlo Sainz - subject of much of this lunchtime's wave of news - hops into the Toro Rosso.

Simon Baker: Let's not get ahead of ourselves, @McLarenF1, external won't suddenly be fighting for poles & wins next year, just be quicker than atm

Stewart: Is this the first engine change of the season for McLaren that hasn't resulted in a grid penalty?

Rik Roberts: I'm really pleased Honda will still be in F1. Their initial stint in Indycar in the 90s was embarrassing, but then they got it right

Andrew Benson
BBC Sport’s chief F1 writer in Singaore

Sainz’s move leaves Palmer without a drive in F1 next season.

The 26-year-old has limited options, with few seats still available. There is an opening at Williams alongside Canadian rookie Lance Stroll but they have not yet decided whether to replace Felipe Massa.

Palmer faces competition there from Williams reserve driver Paul Di Resta, who impressed the team when standing in at the last minute whenMassa became ill during the Hungarian Grand Prix weekend, and possibly Robert Kubica, who is trying to make a comeback to F1 seven years after the horrific rally accident that left him with partial movement in his right arm.

Image source, Getty Images

Andrew Benson
BBC Sport’s chief F1 writer in Singaore

Red Bull have not said who they intend to drive for Toro Rosso next year.

Russian Daniil Kvyat, who has driven for the team since being demoted from the senior team midway through last season, is expected to stay as a benchmark.

The most likely candidate to replace Sainz is Frenchman Pierre Gasly, who won the GP2 championship in 2016 and is winning races in the Japanese Super Formula series this year.

However, Honda is keen to promote its protege Nobuharu Matsushita, who is racing in Formula 2, the renamed GP2, but the Japanese has not yet earned sufficient points for a full F1 ‘super-licence’.

Image source, Getty Images

Stewart‏:The Toro Rosso press releases must be hard to write. They have to talk about how good Honda were, rather than how hopeless they are.

Ant Jarman: Really pleased to hear of @McLarenF1 joining up with Renault Sport Racing from next season. Onwards and upwards!

Keith Murphy: It's all happening in the Formula 1. So much to talk about. Danny Ricciardo sitting P1 after FP1 too.

Andrew Benson
BBC Sport’s chief F1 writer in Singaore

Image source, Getty Images

Carlos Sainz is to join Renault in 2018, replacing Englishman Jolyon Palmer alongside German Nico Hulkenberg.

Renault said Sainz, 23, was on loan from Red Bull, for whose junior team Toro Rosso he has driven for the last three years.

Renault Sport managing director Cyril Abiteboul said: “Carlos Sainz is a a very promising driver who has been on our radar for some time.

“We feel Nico and Carlos will complement each other on and off track and help us push forwards on the grid.”

Sainz, son of the rally legend by the same name, was keen to progress his career and for next season there is no drive available at the senior Red Bull team, where Daniel Ricciardo and Max Verstappen are both under contract.

“To be a Formula 1 driver for a manufacturer team is an honour,” he said, “and I hope to reward Renault’s faith in me with my very best performances on track. The trajectory of Renault Sport F1 team is exciting and I’m proud to join at such an important time in their history.”

Full story.

Image source, Twitter

In other news, I'm finding it very hard to accept that someone who sat in a 2006 Renault F1 car as a mere child is now a fully-fledged grown up who needs to shave more often than I do.

We want your reaction to today's myriad announcements. Get in touch via #bbcf1.

Jack Beecroft‏: These swaps will benefit Red Bull they want their own engine and Honda is more open and dependent on their interference than Renault

Darren Thompson: Whilst it's sad McLaren's risk on Honda didn't work out, at some point they really did have to say enough is enough.

A little graphic to underline the reliability (or otherwise? OK definitely otherwise) of the Honda and Renault engines.

Mercedes and Ferrari look on, suppressing grins.

Image source, .

Franz Tost, Scuderia Toro Rosso team Principal: “Everyone in our team is very much looking forward to working with Honda. Ever since its founder Soichiro Honda entered his motorcycles in events, racing has always been a central part of the company’s ethos. It’s a very exciting challenge and I hope that both parties will gain a great deal from it as we develop together.

"Honda has a long history in Formula 1, dating back to 1964 when it first entered the sport with its own team and, as an engine supplier it has taken five Drivers’ World Championship titles and six Constructors. This heritage, together with the full confidence that we have in Honda’s capabilities to succeed, make me strongly believe that we will achieve a fruitful future together."

Takahiro Hachigo, president & representative director of Honda Motor Co.: “Toro Rosso is an experienced team with a youthful energy and history of nurturing the stars of the future. Everyone at Honda is looking forward to working with Toro Rosso, and we are excited to start this new chapter in our Formula 1 journey with them. I would like to express our appreciation to Liberty Media and the FIA for their cooperation toward the realization of this partnership. Honda and Toro Rosso will work as one team to strive for progress and a successful future together. We appreciate the support of our fans as we begin this challenge.”

Jérôme Stoll, President of Renault Sport Racing:

“This is a strategic decision for Renault Sport Racing. It is the first time that Renault will work with McLaren and we are proud to have reached an agreement with an organisation that has such a rich Formula 1 history. This alliance is not only technical and sporting, but also comes with marketing and communication benefits. We know that McLaren will push us hard on track and this competition will be to the benefit of all.”

Cyril Abiteboul, Managing Director, Renault Sport Racing:

“We are pleased to confirm a new partnership for Renault Sport Racing and McLaren Racing and excited to embark on this new relationship of these two historic brands in Formula 1 cooperating together for the first time. This agreement is perfectly in line with our mid-term strategy and with our objective to be in a winning position as a team in 2020.

We are looking forward to seeing the Renault brand on next year’s McLaren and racing our new partners on track. McLaren is an inspirational team with two talented drivers which should not only support our engine development efforts but also act as a reference and an exam-ple in the ongoing construction of our chassis operations. This is an exciting new beginning with a championship-winning team that is hungry to return to glory.”

Zak Brown, McLaren Technology Group Executive Director:

“Today’s announcement gives us the stability we need to move ahead with our chassis and technical programme for 2018 without any further hesitation.

“As an organisation, McLaren has always worked extremely hard to form lasting partnerships with its technical suppliers. We’re convinced that we can bring real value to Renault Sport Racing as we work alongside it to develop this current power unit into a regular race winner.”

I hope you're all keeping up.

Toro Rosso and Honda have agreed a "multi-year" deal.