Lewis Hamilton has claimed he is feeling "stronger than ever" as he creeps nearer to a fifth Formula 1 championship in 2018.

With victories in four of the last five races, the Briton holds a 40-point lead over main rival Sebastian Vettel with some believing the pressure is already starting to show on the German.

As he has continually stated, however, Hamilton is not about to start becoming complacent even though it is his Mercedes team that currently appear in the ascendency.

"I don’t think you ever have one hand on it [the championship], you either have both hands on it or you don’t," he said in Sochi.

"There's still a long way to go, a lot of points available. Six races are still a lot of races, it's a long season.

"We're really just head down, everyone's working incredibly hard to continue to improve the car.

"We're going to be faced with different challenges as we come to these different races, so the job is still exactly the same. The target is still exactly the same and the approach is still exactly the same."

Also Read:

• Vettel has considered a psychologist to overcome failures under pressure
• Hamilton remains wary of Ferrari threat despite increasing lead in Singapore

The 33-year-old also feels he has made personal progress in how he balances his hectic off-track lifestyle with staying in peak physical and mental condition.

“I feel healthy, happier and stronger than ever,” Hamilton said. “It still feels like it has been a long year.

“But I have had plenty of time to myself and some really good quality time with family. I also got to see some beautiful places and get some good training in, too, so I do feel really good for this last stint.

“First and foremost, I am a racing driver. I am also trying to grow into an entrepreneur and a businessman and be successful in business, but one who drives the socks off his car.”

At the Russian Grand Prix on Friday, the Mercedes driver once again led the way finishing the day half a second clear of Vettel.

“We’ve brought more upgrades this weekend; there’s so much work going on at home,” Lewis revealed.

“It’s just really encouraging when you come to a race and you get an upgrade, knowing that this late in the season we’re also already working on next year’s car – it motivates me to get the best out of everything.”

The four-time world champion is also keen to put two poor years behind him at this race, which has seen him beaten by his teammate on both occasions.

“Sochi has been one of the weaker circuits for me in the past, particularly last year,” he admitted.

“I’ve done a lot of work to understand the balance and see where I can improve to try and rectify this – today has been good in that sense.

“From every race we’re learning more and more and particularly the last few races have helped us to really gauge which foot we need to start on for the weekend.

“It’s been a good day for us, so let’s hope that it continues tomorrow.”

Williams CEO Mike O'Driscoll has called on Liberty Media to implement a "fairer" and "more level" Formula 1 playing field for all the teams after announcing their financial figure for the first half of 2018.

Parent company to the F1 operation, Williams Grand Prix Holdings PLC, revealed a drop in income from £85.9 million in 2017 to £82.6m this year, including a near £5m drop in revenue from FOM to £60.2m from £65.5m.

This has coincided with one of the worst season's in the Grove squad's illustrious history with just seven points from the first 15 races, leaving them pinned to the bottom of the Constructors' Championship.

Even so, O'Driscoll believes the results can be seen as satisfactory for a team in Williams' position.

“We have delivered a solid set of financial results in what has been a challenging half year for our F1 operations, whilst continuing to demonstrate growth in our Williams Advanced Engineering Business,” he reported.

“Revenue and EBITDA in F1 reduced in the first half of 2018, reflecting the challenging financial environment we operate in as an independent team.

"A tough 2018 season on track has demanded additional investment to tackle performance issues, and we have been working through these while also turning significant attention to the design of next year’s car.

“There continues to be a large gap in competitive expenditure between the leading teams and the rest of the grid, and we remain hopeful that the future of the sport under Liberty Media will bring about a fairer, more level playing field for all teams.”

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• Williams play down concerns over 2019 budget

Some are concerned for the future of Williams, with the F1 team set to lose title sponsor Martini and several sponsors once Lance Stroll completes his exit at the end of the year at the latest.

It is thought Williams could do as they have done in recent years and focus on drivers who bring significant backing to make up for that loss, but their CEO insists the foundation is still strong.

“Although we continue to face challenges in a very dynamic environment, we are well placed to respond. With world-class facilities and a strong and talented organisation, Williams remains determined to succeed,” he concluded.

Haas F1 have confirmed they will field an unchanged line-up for the third straight year in 2019 retaining both Kevin Magnussen and Romain Grosjean for next season.

The American team had hinted that an announcement was expected before the Japanese Grand Prix in a week's time and then caught a few off-guard by doing so early on Friday morning in Sochi.

It's a largely expected move given the performance of Magnussen for much of this year while Grosjean overcame a tough first half, littered with errors and crashes, and has produced solid results since.

"From the very beginning, we needed experienced drivers to hasten the development of our car and our team, and we have two very good and experienced drivers in Romain Grosjean and Kevin Magnussen," said team boss Guenther Steiner.

"We’ve improved drastically from last year to this year, so retaining both drivers was a pretty easy decision."

Indeed, Haas has become a much stronger and much more consistent midfield threat this year and sit just 15 points behind Renault in fifth in the Constructors' Championship.

"I think the 100-point barrier should be and will be broken, and we’ll do it with Romain and Kevin,” added Steiner.

"Both drivers push each other to be better, and their collective feedback allows us to be better. It’s not a coincidence that in their second year as teammates, Haas F1 Team is having its best year.

"By keeping Romain and Kevin together, we aim to do even better next year."

For Grosjean, his retention marks his continued presence in the building of the Haas team, having been there from the start in 2016.

"It’s impressive to see what this team has accomplished in such a relatively short time. I take a lot of pride in the time, effort and sacrifice we’ve all put forth to make Haas F1 Team so competitive," he said.

"Gene Haas has built something very special – something we can make even better – and it’s an honour to be a part of it."

For Magnussen, this is another key example of how he has progressed since the difficult years with McLaren and Renault.

"I’ve never been in a better situation than the one I’m in here at Haas F1 Team," said the Dane.

"This is a team filled with racers and we’re all striving for the same thing. There’s no bureaucracy and everything is very straightforward.

"Gene Haas is all about efficiency, and he and Guenther Steiner have created a very efficient environment that gets the best from its people.

"We all believe in each other and that’s why we’ve achieved as much as we have."

Daniel Ricciardo admits he expects the reality of his pending departure from Red Bull to set in after the Abu Dhabi Grand Prix in November.

The Australian is heading to Renault for 2019 but will bring to an end a decade's long association with the Austrian energy drinks giant, who helped him through the junior series into F1 with Toro Rosso before joining the senior team in 2014.

Despite what he knows will be a difficult moment at Yas Marina, he also reiterated why he made the bold decision to join the French manufacturer.

“It feels mostly real – but honestly, I think when the chequered flag drops in Abu Dhabi, and I take off the Red Bull overalls for the last time, that’s when it’s going to hit me,” he said to the company's official website.

“It’s not so much the ‘moving to Renault’ part, as it is the ‘closing the book on this part of my career’ bit. From an emotional point of view, that’s when it’s going to hit me.

“I’ve been wearing a Red Bull helmet for over a decade now. It’s been a fun journey and we’re certainly not splitting on bad terms. I’m ready for something new.

“I’m going to be 30 next year and I felt like it was time for the next part of my adulthood," he concluded.

Many have questioned whether joining a team still in a development stage is a wise move for Ricciardo, however, particularly with Executive Director Marcin Budkowski playing down expectations going forward.

“We are 1.5 seconds off the top guys, and if I was sat here thinking we are going to recover that against people like Mercedes and Ferrari, these massive organisations, with super competent people, [I would be wrong]," he was quoted by PlanetF1.

“We have grown over the last two years, but they have had structures with 900 people for many years. Stability has been a benefit to them, so it would be ludicrous for me to say we are going to beat them next year.

“Our objective is to continue progressing strongly, and to be honest, reducing that gap is a real achievement. I certainly hope we can fight much closer to them in 2020. But I am not going to make any predictions because it would be unreasonable."

Also Read:

• Red Bull targeting Mexico as last realistic win chance in 2018
• Prost sure Renault investment in Ricciardo will be "justified"
• Hamilton praises Ricciardo for 'being different' with Renault move

Force India driver Sergio Perez believes the seven-time Grand Prix winner's decision is a good thing for F1.

“Ricciardo to Renault, it’s quite an interesting one," he told RaceFans. “To be someone like him in the midfield will just show how strong the midfield is at the moment.

“If things stay the same for next year and the midfield is so close together he’s going to enjoy a lot of competition.”

Lewis Hamilton and Mercedes hold the early advantage after setting the fastest time of Friday practice at the Russian Grand Prix.

Though it was Sebastian Vettel who led the morning session for Ferrari at Sochi, the championship leader and his Brackley-based squad, who are undefeated in all four previous races at the Olympic Park, pulled ahead in the afternoon.

Hamilton's best time of 1m33.385s came on his third flying lap while using the Hypersoft tyre during the traditional lower fuel runs in FP2 and gave him a two-tenths advantage over teammate and 2017 winner in Russia, Valtteri Bottas.

Interestingly, it would be Red Bull who got closer to the Silver Arrows with Max Verstappen and Daniel Ricciardo both four-tenths back in third and fourth respectively.

Vettel would end Friday over half a second behind Hamilton in fifth as optimising the performance of the pink-striped compound appeared their biggest problem, indeed teammate Kimi Raikkonen would be over a second off the pace in sixth.

The only positive for the Scuderia is the looming engine penalties for Red Bull, which will drop both their drivers to the back of the grid after qualifying.

More worryingly for Ricciardo, he lost out on a good portion of the morning session due to a smoky problem at the back of his car with mechanics still watching the exhaust system in the second practice too.

Surprisingly for Sochi, tyre degradation was one of the main topics of the day as drivers struggled to achieve a prolonged stint with the Hypersoft compound.

Maintaining rear grip was the main issue with so many traction zones, particularly in the final sector, and even saw Vettel spin at Turn 13 during his race simulation.

A one-stop race does still appear the most likely, however, with the Ultrasoft and Soft tyre proving durable enough and, unlike Singapore, the performance gap between the Hyper and Ultra may be small enough to allow the top teams to use the purple-striped compound in Q2.

Entering the midfield where Force India led the way once again, as Sergio Perez and Esteban Ocon moved up to seventh and ninth in the afternoon.

Pierre Gasly hinted at the potential of the upgraded Honda engine being used this weekend in eighth for Toro Rosso, although he along with both Red Bulls, teammate Brendon Hartley and Fernando Alonso will all take grid penalties as a result.

On the week when it was confirmed he would be dropped by Sauber, Marcus Ericsson impressed by beating Charles Leclerc and finishing 10th, despite missing the first session as his replacement Antonio Giovinazzi drove in the morning.

Haas had a busier Friday than most after an overnight garage fire saw two sets of tyres destroyed and then the American team confirmed they would be retaining Kevin Magnussen and Romain Grosjean for a third straight year in 2019.

The performance on track was a little muted though, with K-Mag only 11th fastest albeit six-tenths clear of his French teammate in 15th.

Renault were also further down than expected as Carlos Sainz sat 12th and Nico Hulkenberg 14th although the battle was very close with just four tenths covering P7 to P14.

Bringing up the grid were the two McLaren's and two Williams' once again and the pace of Alonso was the only thing keeping him in touch with the midfield pack in 17th.

Sergey Sirotkin also has the edge on teammate Lance Stroll at his home race after the Canadian flat-spotted a set of tyres in FP1 causing him to lose half the session, putting him at a disadvantage to his Russian partner in the afternoon.

Full results from the second session can be seen below:

Sebastian Vettel has admitted he considered psychiatric help to deal with his tendency to fail under pressure as another potential world champion appears to be slipping away.

The German has come in for criticism for the plethora of mistakes he has made this season, his latest being a collision with Lewis Hamilton at Monza in addition to the race-ending slide into the gravel back at Hockenheim.

Some estimates believe if the Ferrari driver has optimised each situation he could be over 70 points clear of Hamilton in the standings, rather than 40 points behind, however, talking about his mental strength to Auto Bild, doubts a doctor would benefit.

"Of course I have pressure, but most of the time I put it on myself. If you know what you can do and you do not achieve it, then you are not satisfied," he claimed.

"I find the idea very interesting [of getting a psychologist], but I have not met a person that I think can help. I've already researched it a bit, so the whole topic has not passed me by.

"When you have stress, you need to find balance," he added. "I have developed things that work for me and I have enough self-discipline, so as not to be confused."

Also Read:

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• Newey doubtful over Vettel title hopes, Horner disagrees
• Vettel his 'own worst enemy' in title fight with Hamilton

Vettel also insists comments by journalists or pundits don't have a major impact on him, mostly because he doesn't read them.

"In my spare time, I hardly read articles about Formula 1, more about football. I do not let criticism get to me and that saves me dealing with it," he said.

"Generally, my motto is: 'You're never as good as people say and you're never as bad as they say'."

Toro Rosso driver Brendon Hartley insists it is not guaranteed he will leave the team at the end of 2018 despite rumours suggesting he is not in a shortlist.

The New Zealander has struggled for results since making his debut almost a year ago at the United States Grand Prix, scoring just two 10th place finishes this season compared to 28 points by teammate Pierre Gasly.

Now, Red Bull junior Dan Ticktum and Pascal Wehrlein are believed to be the two most likely candidates to join a returning Daniil Kvyat for next year, with the Russian's appointment to be announced this weekend in Sochi.

Even so... “I’m not panicking,” Hartley told Newstalk ZB. “I’m just focusing on doing my job because that’s really the only thing I can do.

“One or two good races and the headlines will be very different. I’m still aiming to be on the grid for next year.

“I have a contract for next year, obviously things can change very quickly.

“There’s been too many times where there’s been potential and it just hasn’t worked out so I’m still keeping the faith so to speak.”

To try and make Red Bull advisor Helmut Marko and team boss Franz Tost reconsider, the former WEC champion knows he has to up his game versus Gasly in the final six races.

“They haven’t given me exact targets,” he said of what would be expected to keep his seat. “In the end, most of the time you’re competing against your teammate so that will be the case for the rest of the season.

“It’s not that he’s always massively faster but there’s been a few occasions where he’s put an incredible race together and he’s got a few points on the board. But both of us haven’t been scoring points in the last races, we haven’t had the car.

“If the car’s not fast enough to score points, which has been the case the last few races, then that will be noted as well.”

Charles Leclerc believes his rapid rise through the junior series all the way to his 2019 seat with Ferrari wouldn't have been likely without the help from Jules Bianchi.

The pair grew up together with the Monegasque racing at a karting track owned by Bianchi's father in Brignoles in the South of France, eventually both becoming members of the Ferrari young driver academy.

Destiny could well have eventually seen Jules and Charles race together for the Scuderia until the former Marussia driver tragically died from head injuries sustained in the 2014 Japanese Grand Prix.

However, Leclerc never forgets the impact Bianchi had on him.

"He has always been a massive help with me. When I started Formula [racing], he was always there," he said to Mobil 1 The Grid.

"At the end of the first day, I would call him and say, ‘This thing I’m not so good [at]’, he could explain it to me and I’ve improved probably a bit quicker than the others thanks to him, because he helped me during my career when he was there.

"He’s definitely truly missed, as a person especially, but also as a help," he concluded.

Tragedy then struck the 20-year-old again during his dominant F2 season in 2017 with the death of his father Herve prior to the Azerbaijan GP weekend.

"It was definitely very hard because I lost him on the Wednesday before the race. It was very, very fresh," Charles remembered.

"The thing I told myself was that [my father] seeing me racing was everything, and he would not want me to be destroyed before the race and do a bad race.

"The only thing he would want me to do was win for him and we won race 1 and we won race 2 on track, although we took a 10-second penalty that put us P2, but in my mind it will stay as a good memory, that weekend, and I’m very happy to have honoured him this way."

Also Read:

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• Ferrari looking post-Vettel with Leclerc promotion, says Eddie Jordan
• Leclerc doesn't expect to feel extra pressure as a Ferrari driver

Next year, Leclerc will achieve his ultimate goal of racing in F1 for Ferrari and vows to keep both Bianchi and his father very much in his mind.

"My father was definitely very proud when I told him I had signed in F1, even though it was a bit earlier than I had really signed," he recalled.

"But at the end, I didn’t really lie because I am here and now in Ferrari, which feels incredible.

"Jules probably deserved this place more than I do and I’m extremely happy to be the one that has his place. I will try to honour him in the way he deserves."

Sergio Perez has reaffirmed his position that there was no deliberate intent to hit Sergey Sirotkin during their battle at the Singapore Grand Prix.

The Mexican had become bottled up behind the Russian after pitting early with a frustrating battle ensuing as Perez couldn't find a way past the much slower Williams.

Eventually, an opportunity did arise exiting Turn 14 with the pair duelling all the way to in front of the main Marina Bay grandstand where the Force India driver appeared to swerve left into Sirotkin's car.

"I’ve obviously seen it and in my opinion, it looks a lot worse from the outside,” Perez told Motorsport.com in Sochi on Thursday.

“Basically, with these mirrors it’s very hard to see behind, so I lost the reference, I thought I already did the move in the first corner, entering the Turn 17/18 chicane.

“I actually was speaking on the radio at that point but then I saw him, and then I just misjudged where he was. I was trying to close the door before braking but he was just too close to it.

"It was just my fault, got a penalty, which I think was right. Nothing to say, really, other than accepting my mistake. I ruined my race, I wouldn’t have done it on purpose.”

Also Read:

• Ocon got Perez apology after first corner clash in Singapore

Some drew comparisons between the Perez/Sirotkin clash to when Sebastian Vettel intentionally hit Lewis Hamilton in Baku last year and therefore thought the 28-year-old should have been disqualified.

The reason for possible intent was a complaint Sergio put in about the Russian driver moving around under braking.

“There wasn’t a single time where I moved under braking,” Sirotkin said in response.

“It shouldn’t be mixed up with... in Singapore, when you approach braking zones, you don’t always approach in a straight line, and it’s simply a question of at which point you put your car at the angle to brake straight.

“I was honest in my position after the race, claiming that I did nothing wrong and this is my conclusion still.”

Esteban Ocon admits he was "upset" by Renault's decision to backtrack on a contract offer for 2019 but does still have a final chance to make the Formula 1 grid.

The Frenchman's dilemma has been one of the closest followed in recent weeks with an exit from Force India looming at the end of the year at the latest and no lucrative choices elsewhere.

Back at the Hungarian Grand Prix, however, all appeared bright for his future with a contract at Renault seemingly on the brink of being signed before Daniel Ricciardo snatched it during the summer.

“I was surprised when Renault signed a contract with Daniel Ricciardo. Renault has explained that it was because I was in the Mercedes programme, but I do not agree with Cyril Abiteboul,” Ocon said in Sochi

“Yes I’m a Mercedes driver, but if I was in a Renault that wouldn’t matter. I’m a little upset that as a sportsman, it’s not only your sporting achievements that matter.”

His most likely chance appears to come with Williams, a Mercedes customer, but some don't believe it would be a good idea for the 21-year-old based on their current lack of competitiveness.

Also, as Ocon himself pointed out; “I don’t know whether I can go to Williams,” he told France's TF1 as his lack of sponsors may not meet with the Grove outfit's need for revenue.

“We are negotiating and we hope that everything will work out. Not having a contract for next season is not a catastrophe but you never know how things will develop in F1.

“What I can promise is that next year I will do my best to be back in the championship in 2020.”

Also Read:

• Rosberg defends young driver programs despite "terrible" Ocon plight
• Williams monitoring Stroll/Force India move "race-by-race"
• Wolff blasts "hidden agendas, politics' for Ocon situation

A final lifeline may just come from an unexpected source with Haas not ruling out taking any driver, regardless of manufacturer backing, for next season.

“You always consider because they are both good drivers,” Steiner said, including current F2 championship leader George Russell in his comments.

“But then again we need to look after ourselves and I think the problem is for Mercedes."

The Italian also claimed a decision is likely before the Japanese GP in two weeks time.