Ahead of his home race in Brazil, Felipe Massa has announced he will retire from Formula 1 at the end of the 2017 season after 15 years in the sport.

The 37-year-old's future has been uncertain with his current Williams team assessing several options to replace him for next year, with former Renault driver Robert Kubica and current reserve at the Grove outfit Paul di Resta both completing two tests in the 2014 car at Silverstone and the Hungaroring.

Other names have been mentioned too, including Pascal Wehrlein and recently Daniil Kvyat, therefore, Massa, who was also in the frame, has apparently decided to take matters into his own hands by deciding he will not continue.

“As everyone knows, after announcing my retirement from F1 last year, I agreed to return this season to help Williams when the call came," he began in a video posted on Instagram. "I have now enjoyed four great years with the team, but my career in F1 will finally come to an end this season.

"Once more, I would like to say a big thank you to everyone who has supported me throughout this time: my wife and my father, my whole family, my manager Nicolas and all my friends, colleagues and sponsors. I would also like to add a huge thank you to all of the fans who have been incredibly supportive and passionate over the years.

"I take so many great memories with me as I prepare for my final two races in Brazil and Abu Dhabi, and although they will be emotional, I am looking forward to ending on a high note and preparing for a new chapter in my career.”

Massa's departure brings to an end a 15-year career flooded with highs and lows, including an eight-year stint at Ferrari which saw him claim 11 wins and famously come to becoming the champion in 2008.

In 2010, he would return from a near-fatal crash in qualifying in Hungary the previous year when he was hit on the head by a flying spring but wouldn't reach the same levels he had before instead playing number two to Fernando Alonso. A move to Williams in 2014 resurrected his career with podiums across 2014 and 2015.

A major factor in his decision is likely the upcoming Brazilian Grand Prix with the Sao Paulo native wanting to enjoy his final home race and hopefully repeat the emotional scenes from his premature farewell last year though without the mid-race crash.

“I would like to thank Felipe for all he has done for the team over the last four years," William Deputy Team Principal Claire Williams said. "It has been an absolute pleasure to work with him.

"We are especially grateful that he agreed to postpone his retirement from F1 for a year after Valtteri joined Mercedes, which demonstrated the depth of the relationship we built during our time together.We appreciate that it wasn’t an easy decision for him to return, after having such an emotional send-off at the end of last year.

"On behalf of Sir Frank, and all the team, we give our very best wishes to Felipe for the future.”

What will that future bring? Well previously Massa has admitted an interest in Formula E but for now, he will look to enjoy his final two races as an F1 driver.

Formula 1's Managing Director of Motorsport, Ross Brawn believes Lewis Hamilton could potentially threaten Michael Schumacher's record of seven world titles after claiming his fourth last weekend in Mexico.

The Briton was one of the influential members of the Ferrari team that the German legend was a part when he won five straight championships between 2000 and 2004 in addition to his two titles with Benetton in 1994 and 1995.

He was also team boss when Hamilton made his move from McLaren to Mercedes in 2013, a switch which has seen him win the crown three times in the five years he has been at the German manufacturer.

Congratulating the 32-year-old on his latest achievement, Brawn said: “Lewis deserved this title, the fourth of his incredible career. For much of the season he was chasing the leader, but after the summer break, he found another gear.

"It's true that the way in which he clinched the crown in Mexico was unusual, it's not often a title comes your way when you've been lapped," he added. "However, I have personal experience of the fact that, as you approach the final small step, it can actually prove more difficult than the previous ones. It was probably one of those cases."

Brawn also pointed to his run of five wins in seven races since August as proof of his standing among the best drivers ever to step in an F1 car.

"It's not just a fourth title that promotes Lewis to the level of the greatest in our sport, the Schumacher's, Senna's and Fangio's. It's the way he drove this year that really impressed me, especially in recent races," he commented.

“Even when his car was not at 100% he was able to produce some amazing drives, so really, congratulations to him for a superb achievement."

With Mercedes likely to remain strong contenders for the title in the coming years and Hamilton keen to continue and test himself against the rising stars, Brawn does see a path that could see the British driver become a seven-time champion.

"I think they are," he told Sky Sports on if Schumacher's records are under threat. "When that happened I couldn't imagine it being beaten but looking at the way that Lewis is performing they could be."

On his future, Lewis has revealed he expects a new deal, reportedly worth $120m over three years which would take him 2021, to be completed soon.

“It is quite an easy process for us,” Hamilton said. “We already have something in place and it’s really just about extending it and enhancing it, working on what more I can do for them, for the sponsors, the brand and vice versa.

“But I’m pretty sure within the next month or so we will have had time to have sat down. Now all the pressure is off, we can go and enjoy these next couple of races.”

Opportunities to compete outside of Formula 1 have made Fernando Alonso into a "racing monster", according to McLaren Executive Director Zak Brown.

The American made the quip in the wake of announcing the Spaniard's second foray into alternative series in a year as he follows up his Indianapolis 500 appearance by joining the United Autosports team the Rolex Daytona 24 Hours in January.

It may not be the only endurance race the double F1 champion participates in next year either, with suggestions the Daytona run could be a precursor to a tilt at the Le Mans 24 Hours as he continues his aspirations of completing motorsport's Triple Crown.

"We'd had some light conversations, we talk about different racing all the time, and I was with Fernando and Luis [Garcia Abad] his manager and he said 'I want to do Daytona'," Brown was quoted by PlanetF1.

"I'm kind of getting used to it after Indy! I turned around to Luis and said 'he's serious isn't he?' And he said 'oh yeah' so I didn't have to ask twice. We've created a monster – a racing monster!"

In a year that has seen Alonso's future be one of the main stories, he has continued to claim F1 and a third title remains his number one focus but away from that the 36-year-old also wants to be considered one of the greatest all-round racing drivers ever.

"My plans for motorsport are much greater than anyone can think," he said in Mexico. "I want to be the best driver in the world and to do that you need to win in different series, compete in different cars and sometimes you need to go out of this small world of F1.

"Motorsport is more than F1,"  Alonso added.

Mercedes Motorsport boss Toto Wolff hasn't exactly given the proposals put forward for changes to the engines in 2021 a thumbs up, insisting nothing has yet been agreed between the FIA, Liberty Media and the manufacturers.

In a meeting of the Strategy Group on Tuesday, the governing body released the initial ideas put forward after a series of talks between the relevant parties with the aim of cheaper, simpler and noisier engines units, three of the main criticisms of the current hybrids.

More revs, no MGU-H but the retention of the same 1.6-litre V6 along with a more powerful KERS were the main takeaways, however, as would perhaps be expected for the team that has benefitted massively from the current power units, the Mercedes boss was cautious in his reaction.

"The concept sounds similar to what we have now but it means a completely new development that will mean we are working on two engines at the same time between 2018 and 2020," Wolff explained.

"It's a vision rather than a regulation and it's their vision rather than the manufacturers," he added. It is important to define all together what F1 should be in 2021, not just from the point of view of the engine.

"What we have is the starting point of a dialogue rather than something we have agreed to. Certain things are right, but it's not quite there."

The Austrian is also concerned that, though reducing costs in the long-term is the goal with the new engine rules, the period between now and when the new engines are introduced will require greater financial investment.

“All of us accept that development costs and sound need to be tackled, but we shouldn’t be running away with creativity in coming up with new concepts because it will trigger parallel development costs over the next three years,” Wolff said.

That point also has the backing of one manufacturer that is more in favour than some of ending the current regulations and that's Renault, who has been third best behind Ferrari and Mercedes pretty since 2014.

“It is a new engine with lots of gimmicks, but it is a new engine and that is really for me the most fundamental element," Managing Director of the Sport division Cyril Abiteboul stated.

“We need to be extremely careful because each time we come up with a new regulation that will come up with a new product – new engine or new chassis – we all know what is the impact. It is going to open an arms race again, and it will open up the field once again.”

Williams Technical Director Paddy Lowe is playing down suggestions of a rift growing between the team and Felipe Massa as deliberations over their 2018 line-up continue.

With the Brazilian's chances of staying appearing to be slim, he has become increasingly critical in his comments towards two drivers known to be in the frame to replace him after completing two tests with Williams recently, Robert Kubica and Paul di Resta.

But, despite potentially having just two races left in Formula 1 amid the uncertainty, Lowe claims the distraction is not affecting how they work together at the racetrack.

"It's something that we're managing internally. Relationships between teams and drivers around renewals is always tense, unfortunately," the former Mercedes boss admits.

"Most of us when we got and apply for a job, it's done in private. In F1 it's a very public affair and that does make it more awkward than we'd like but Felipe's a great guy, and he's got a great relationship with Williams, it's very respectful both ways. Whatever we conclude together, we'll remain on good terms."

12 months after what was thought to be an emotional farewell, next week, Massa will head back home to Interlagos for what again could be his final home race in F1 with the 37-year-old hoping a decision would be in place.

"We're talking all the time to Felipe, and we'll see where we get to with that. There are all sorts of scenarios," Lowe added.

As for the man himself, however: "For sure I will not wait until December," he said. "I don't put a timeline but I hope it will be in the next weeks, so I don't want to arrive in the last two races not knowing about my future. So we will wait and see what the decision is going to be and I hope it will be soon."

Another twist comes follows the admission of another new name joining the list of potential options following Daniil Kvyat's dropping from the Red Bull program.

"As I said in Austin, we are considering all drivers who are not contracted," Lowe said. "That is a fact. Kvyat is a very respectable driver so he should be in the frame."

Carlos Sainz hopes former Toro Rosso teammate Daniil Kvyat will get the chance to race in Formula 1 again in the future after being permanently dropped from the Red Bull program following his last appearance at the United States Grand Prix.

The Russian was drafted back in for the race in Austin after losing his seat to Pierre Gasly from the Malaysian round, though he performed well, finishing 10th, it wouldn't be enough to save his future as advisor Helmut Marko confirmed it would be the last time he competed under the Red Bull banner.

It was the final nail in the coffin following 18 months of misery which began with Kvyat being demoted back to the junior team after his home race in Sochi last year and has now culminated in the 23-year-old needing a new path in his career.

"We joined the Red Bull programme on exactly the same day in 2009, and in 2010 we did our first year. I was hoping to have him also in F1 for many years, and I hope I find him back in F1 soon," Sainz said reflecting on his relationship with the former GP3 champion.

At the same time, however, the Spaniard, who has now joined Renault until at least the end of 2018 on loan from the Red Bull stable, admits it is the price some have to pay for not meeting the requirement of those who have helped your racing career grow.

"It's probably the toughest platform out there," he claimed. "It's the one that gives you the most, but it can also take away everything that it gives you.

"For me, and I think for everyone that has even been dropped by Red Bull or given a chance, I think without them we would have never had a chance to drive an F1 car or compete in F1. They are very tough, but they have reasons to be tough."

Also in Mexico, Red Bull team boss Christian Horner defended the decision to drop Kvyat, believing he had been given sufficient opportunity to prove himself after the disappointment of what occurred last season.

"Dany Kvyat has obviously had a large investment from Red Bull over the years," he stated. "He had the opportunity to step into Red Bull Racing and compete in the 2015 season and the start of the 2016 season with the team.

"Formula 1 is a tough business and unfortunately Dany didn't do enough, in our opinion, to warrant retaining that seat but we still believed in him and he was given a second opportunity, which is very unusual in Formula 1, to retake the seat with Toro Rosso.

"And then from there we obviously have other juniors that we have invested in that are knocking on the door of F1."

Those juniors are Gasly, who finally has his chance after winning the GP2 title last year and Brendon Hartley, a driver that knows what it's like to be dropped from Red Bull but is being given a second chance in F1 after several successful years in the WEC.

Mercedes Motorsport boss Toto Wolff insists there is no disappointment at seeing Max Verstappen pledge his future to Red Bull until 2020 following speculation the world champions were considering the Dutchman for 2019.

The 20-year-old was thought to be considering his future at the Milton Keynes outfit after a difficult 2017 marred by reliability problems and a general lack of results but strong recent progress with two wins in the last four races and some persuading by team boss Christian Horner was enough to get Verstappen to sign an extension.

Undoubtedly, that will have caused a few sighs at their rivals, who now have to contend with Formula 1's rising star potentially leading the re-emergence of one of the sport's current powerhouses, but Wolff sees his rival's motives for doing a deal early.

"I think Red Bull was very keen in extending Max's contract by a year, in order to make sure that he stays there for the next three years," he said. "If I were in Red Bull shoes, and I believe in his abilities, probably stability is important and so far absolutely understandable from myself."

The Mercedes chief also claimed no effort was made to sign Verstappen when asked if there was any sadness on missing out on arguably F1's most valuable commodity.

"Absolutely not. Why should I be sad?” he replied. "We see there are strong drivers all through the top teams now, and it doesn't come unexpectedly. And to be clear, we've never talked to him about a contract."

The recent moves made by Red Bull have led some to wonder if the three-time Grand Prix winner is now the lead driver at the team at the expense of Daniel Ricciardo, but advisor Helmut Marko suggested it was, in fact, the Australian causing the shift as he holds back over his future.

"We started with Max in F1, he had his first victory and now we want to achieve the championship title as the youngest ever F1 driver," he said. "Yes, both drivers, Max and Ricciardo, could have been free after '18 so we tried to secure at least one driver because Max asked if we could make a deal to 2020.

"Ricciardo was putting himself on the market,” Marko added. “So now we are talking with him."

Max's decision to stay was also welcomed by father and former F1 driver Jos Verstappen, who praised Red Bull's efforts during the season.

"The team has moved heaven and earth to become more competitive again," he told Holland's Ziggo Sport Totaal.

"When you look at the state of the car at the beginning of the season and how good it is now, that answers the question of what makes a top team. All the changes made fit wonderfully with Max's driving style, it is noticeable on the stopwatch."

Former Formula 1 CEO Bernie Ecclestone claims efforts by the FIA and potentially even Mercedes have been made to help Ferrari more competitive for the good of the sport.

The issue of biased towards the Italian team was reignited following the United States Grand Prix when a controversial penalty was handed to Max Verstappen for going off track and gaining an advantage promoting Kimi Raikkonen back onto the podium.

Though Ecclestone would not comment on the incident in Austin, instead he spoke of wider efforts that have been made for the good of the Scuderia during his time in charge.

"F1 is Ferrari, and Ferrari is F1," the Briton, who remains Chairman Emeritus, told Italian newspaper La Repubblica. "Helping Ferrari has always been the smartest thing to do. It was always done through the technical regulations.

"The teams are important to F1, but Ferrari is more than that. So many things have been done over the years that have helped Ferrari to win."

2017 saw a sweeping change in regulations which surprisingly saw Ferrari as one of the main beneficiaries, becoming legitimate contenders to Mercedes after three years of domination.

What has been noticeable is, despite the increased aerodynamics this year, engines have remained the key performance indicator and to that end, Ecclestone suggested that perhaps the German manufacturer had helped improve their power unit.

"Certainly at one point they had help with this engine," he stated. "It's the same for Mercedes as it is for the others -- a world championship win against Ferrari is always worth more. If Mercedes decided to transfer technology to Maranello, I say it was a good move.

"What is certain is that this friendly situation between the two teams is the best thing for Mercedes, it means Red Bull did not have the most powerful engines and Ferrari was competitive enough to be a credible rival to beat," he added.

In other comments, however, another controversial F1 figure, former Benetton and Renault boss Flavio Briatore, thinks Ferrari isn't helping itself by keeping one member of the team.

"Certainly it is very difficult to win the Constructors' title with [Kimi] Raikkonen," he said to Spanish daily Marca. "To win, you must have two drivers who are competitive and then you identify who should win the Drivers' Championship."

The flamboyant Italian, who remains linked with Fernando Alonso, also claims the Maranello outfit isn't as strong as that in Brackley.

"You win and lose races but a championship is more like the Giro d'Italia," he said. "Lewis and Mercedes have been the strongest, even if Ferrari did very well at the beginning but I think Mercedes did the better job in development."

Chairman Sergio Marchionne has claimed Ferrari would be more than happy to end their participation in Formula 1 after 2020 after voicing unhappiness over the plans of new owners Liberty Media.

The two sides haven't exactly got along since the Americans took over as Commercial Rights Holder last year especially after one of the first criticisms of the sport by Liberty was at Ferrari's $100m bonus payment they receive.

Now the Italian team is once again trying to establish the high ground in future negotiations by issuing yet another threat to leave the sport should future changes not suit their desires with the latest area of contention the newly unveiled engine proposals for 2021.

"Liberty has got a couple of good intentions in all of this, one of which is to reduce the cost of execution for the team, which I think is good," said Marchionne on Thursday. "[But] there are a couple of things we don't necessarily agree with.

"One is the fact that somehow powertrain uniqueness is not going to be one of the drivers of distinctiveness of the participants' line-up. I would not countenance this going forward."

It is true that CEO Chase Carey has previously said the engines are too influential in determining performance but in recent years Ferrari has invested heavily to bring their current engine near to the level of Mercedes while also and would likely not want to see that wasted by the introduction of more changes.

Their problems with Liberty are more broad, however, and mostly stem from the financial aspect of the new leadership keen to see a levelling of the playing field with more equality of revenue distribution.

"The fact that we now appear to be at odds in terms of the strategic development of this thing, and we see the sport in 2021 taking on a different air, is going to force some decisions on the part of Ferrari," the Chairman claimed.

"I understand that Liberty may have taken these into account in coming up with their views, but I think it needs to be absolutely clear that unless we find a set of circumstances, the results of which are beneficial to the maintenance of the brand, and the marketplace, and to the strengthening of the unique position for Ferrari, Ferrari will not play."

Further future proposals, including the first test of a budget cap in 2019 according to Germany's Auto Motor und Sport, are set to be revealed by Liberty in a meeting of the Strategy Group on November 7th and Marchionne insists Ferrari is going in those discussions open-minded.

"I don't want to prejudge any of this," he said. "We're walking into this meeting next Tuesday with the best of intentions, we'll see where it takes us."

But he further stoked the flames by suggesting the thought of something so incomprehensible as F1 without Ferrari would actually be welcomed in Maranello.

“It would be totally beneficial to the P&L [profits and losses]," he declared. "We would be celebrating here until the cows come home.

"What I do know is that it [F1] has been part of our DNA since the day we were born, it's not as though we can define ourselves differently, but if we change the sandbox to the point where it becomes an unrecognisable sandbox, I don't want to play anymore."

Renault Sport Managing Director Cyril Abiteboul has admitted the company misjudged the impact of racing at high altitude in Mexico and likely pushed their engines too hard leading to problems.

Four of the six cars using the engines had to retire from the Grand Prix this past Sunday with Toro Rosso driver Brendon Hartley suffering two failures in qualifying and the race. Concerns over Daniel Ricciardo's unit led to a change before the race and then the MGU-H on the new unit would fail after just six laps.

The two works Renault cars would also retire, yet all this was offset by Max Verstappen claiming a comfortable victory for Red Bull, some 20 seconds clear of Valtteri Bottas' Mercedes in second.

"We've made an error in the judgement in our preparation in the way we have been trying to balance performance versus reliability," Abiteboul told Motorsport.com.

"It's clear when you look at the pace of the car around the weekend, lots of teams have come here taking the right approach when it comes to dealing with engine parameters and chassis parameters.

"We're extremely competitive. The flip side is that we weren't capable of being at the right level of reliability for that level of performance. At the same time, it's a judgement that has allowed a car powered by Renault to be on the top step of the podium."

Acknowledging it was the thinner air which caused the overheating, as it more pressure on the ERS unit to make up the performance loss from V6 engine, the Renault boss concedes a more conservative approach should have been taken

"It's the climatic conditions but we knew that," Abiteboul said. "We have been racing for two years here, we know what to expect there is no excuse.

"We [need to] maybe take a bit more of a humble stance and accept the fact that the engine needs to be managed. We have to understand what went wrong in the preparation for the next race."