On what could well be a championship-deciding weekend, Lewis Hamilton believes he produced "one of the best" qualifying and race simulations of his career at the Mexican Grand Prix, following an earlier spin.

The combination of reduced downforce at higher altitude and a dusty track at the Autodromo Hermanos Rodriguez meant even the faster 2017 cars were struggling to maintain the grip on Friday, with the Briton simply one of the many to have an off-track moment.

In general, Mercedes look set for a bigger battle than recent races, with Red Bull emerging as strong challengers following Daniel Ricciardo's table-topping time in the afternoon.

More frustratingly, Hamilton's high-speed spin, midway through the Esses, came as the team were evaluating race tyre performance, but his later work would leave the 32-year-old much happier than perhaps he expected.

“It's been a good day today,” he said. “It didn't really start out great, particularly in the second session with the big spin on my first lap [at Turn 9], that really threw off the session and obviously made it a little bit tricky to get the run on the Supersoft.

"I put myself on the back foot but the single lap and then the long run on the Ultrasoft was probably one of the best I've ever done," Lewis claimed, "I don't think I've ever done 26 laps that consistent, apart from in the race may be. We got lots of information, the track was feeling better in the second session once the temperature came up.”

Quickly becoming one of the standout races of the year for fans and drivers alike, Hamilton would also thrilled by the Friday turnout in Mexico.

“It was great to see all the fans buzzing already today, in the paddock but also in the big grandstands,” he gleamed, “so overall a good day.”

Across the garage, Valtteri Bottas had a mixed day, topping the times in the morning with what was still the second-best lap all day, but the Finn was left disappointed after losing that initial sweet spot later on as he dropped to the bottom of the top three teams in sixth.

“First practice was good; I really enjoyed it. It is such a fun circuit to drive because it has quite a low grip, so it is definitely challenging,” he said.

“We made some set-up changes for FP2 which went in the wrong direction, so in the end of the session, we went back to the original set-up. For some reason I also struggled to get the tyres to work in the second session, that's why it didn't look as good as the first one. But I think it was a positive day overall, I'm looking forward to qualifying.”

Fernando Alonso will compete in the 2018 Daytona 24 Hours in January, teaming up with European F3 champion Lando Norris and Phil Hanson behind the wheel of Ligier LMP2 car run by United Autosports, owned by McLaren Executive Director Zak Brown.

The news was widely expected after rumblings of an entry began last weekend in Austin when it was confirmed the Spaniard would be staying with McLaren for at least one more year.

It is thought the Daytona appearance could be a precursor to a run at the Le Mans 24 Hours, another leg of the Triple Crown, and commenting on his announcement, the double F1 champion is keen to gain experience of yet another type of racing.

“What an exciting and interesting project,” Alonso said. “Learning about a completely new racing category, adapting to a different car and to another style of driving and everything that goes with it, is a new challenge for me and I can’t wait to test myself again as a driver.

"The Daytona 24 Hours is the most iconic U.S. endurance race and one of the world’s great races. Everyone knows it.”

This latest foray away from F1 comes after a highly successful attempt at America's most famous motor race, the Indy 500, in May this year and was noticeable for the large addition attention is brought to the oval race.

Commenting on having the Alonso attraction now heading to Florida, IMSA President Scott Atherton hoped his presence would have a similar on the race at Daytona. 

“We are absolutely thrilled to welcome Fernando Alonso to IMSA competition in the Rolex 24 At Daytona,” he said. “It’s not possible to overstate the significance of this news. There is no question that with his F1 experience and how competitive he was at the Indianapolis 500, he will be an immediate contender for the Rolex 24 victory.

“We are especially grateful to Zak Brown and the United Autosports team for creating this fantastic opportunity for our sport’s biggest race. The Rolex 24 has had its share of racing legends compete – and win – over the years, and it will be fascinating for fans here and around the world to watch Fernando and the team pursue this highly coveted prize in January."

Brown himself added: “I’m thrilled we have managed to put a deal together to get Fernando in the car at Daytona.

“Although he hasn’t driven an LMP2 car before I’m confident he will pick it up quickly. He’s one of the best drivers around so it will be great to have him as part of the team, not only for his speed but for his experience and the invaluable knowledge he will pass onto Phil and Lando.”

Alonso won't be the only current F1 personality racing with current reserve and 2018 Williams hopeful Paul di Resta also teaming with United Autosports in their second car entry.

Daniel Ricciardo backed suggestions of a big battle for the victory at the Mexican Grand Prix after moving Red Bull to the top of the timesheets in Practice 2, beating the Mercedes of Lewis Hamilton by a tenth of a second

The Australian posted a 1m17.801s, faster than Valtteri Bottas best on the same tyres in cooler morning conditions, to lead the champion-in-waiting in what was an eventful afternoon in Mexico City.

The action began with an early red flag caused by Romain Grosjean in the Haas. The Frenchman lost the rear of his car after being wide coming onto the main straight, he would get going again but the flat-spotted right-rear tyre would fail as he got back up to speed sending rubber and carbon fibre flying.

The damage to the floor of his car would also be substantial and left him unable to run for the remainder of the session.

Cars dropping out early would be a theme as Max Verstappen, who finished third overall in the second Red Bull, had his day ended prematurely following the failure of an engine that had reached its limit on mileage.

In his first session back since Japan, Pierre Gasly, who is already set for a grid drop, also had to park up due to a Renault engine failure.

On the track, the drama would continue as, once the Haas was cleared, Hamilton produced a rare error losing his car at Turn 9. Lucky to avoid contact with the wall, the incident could hamper Mercedes' race preparations as he and teammate Valtteri Bottas had started tyre comparisons between the Supersoft and Soft during a long run.

On a weekend where Sebastian Vettel must win to keep his slim title hopes alive, he had his own problems at Ferrari after a fire extinguisher failure under his seat caused the foam to leak into seat causing a burning sensation in his overalls.

A quick change of clothing and all was OK, but the pace appears doesn't appear to be there for now with the 30-year-old only fourth fastest overall ahead of teammate Kimi Raikkonen.

After leading in the morning, Bottas would drop back to sixth in Practice 2 in the other Mercedes, some four-tenths slower than he managed earlier in the day.

Despite a grid penalty, Fernando Alonso opted to do a second low-fuel qualifying-style run which would see the Spaniard leapfrog Sergio Perez into seventh. Interestingly, almost all of the gap between himself and Ricciardo would come in Sector 1, which is dominated by straights.

Nico Hulkenberg put almost three-tenths between himself and Renault teammate Carlos Sainz as the German was 9th and the Spaniard 11th. In between, the ever-present Esteban Ocon in the second Force India making his first appearance after missing the morning.

Williams has some work to do with Felipe Massa 12th and Lance Stroll 14th, the Canadian would also lightly hit the wall at Turn 5 following one of many slow-speed spins in the session, as grip remained poor, though little damage was done.

Brendon Hartley split the two Grove cars in 13th, with the New Zealander looked to make up for missed time in Practice 1 following engine mapping problems.

Stoffel Vandoorne, having switched to a Spec 3.7 Honda engine would suffer a loose wheel exiting the garage but noticed in time to stop in the pit-lane, get it secured and eventually finish 15th.

Pascal Wehrlein would lead the Sauber charge in 16th, beating the Haas of Kevin Magnussen, as the American team's concerns before the weekend prove well-founded.

Mercedes motorsport boss Toto Wolff believes his team will face a "difficult" fight to complete a job that is only half done in his eyes and secure the Drivers' Championship for Lewis Hamilton at the Mexican Grand Prix.

The Briton needs a top-five finish to claim a fourth Formula 1 title and complete a quadruple-double for the German manufacturer after they clinched the Constructors' crown last weekend in Austin.

Yet reflecting on what was a "special" result and a "very proud achievement" for Mercedes, Wolff was more impressed by how Hamilton went about clinching his seventh win of 2017.

"Just as important was the way we won the race, claiming pole position and then controlling it from the front, after passing our direct rivals on track," said the Austrian.

“That kind of performance confirmed we are continuing to develop the car in a good way - and applying the learning from our difficult days, to iron out the inconsistencies we saw earlier in the season.

“Lewis is doing a superlative job, and we saw he was in control of the race at every single point," he added. "Valtteri got swallowed up by the cars that converted to two stops, but he showed very strong pace during the Grand Prix and took another step forward in how he was using the car. There is still more to come from him.”

Looking ahead to this weekend in Mexico City, though the title race appears to be a foregone conclusion, Wolff insists Mercedes will continue the same approach they have had as they leave nothing to chance.

“When we set our targets at the start of the year, it was to become the only team to win both championships across a major regulation change," he stated. “We now have to complete that job with Lewis, who is in the best possible position with three races remaining.

“We know that anything can happen in this sport and that the tables can be turned on you very quickly. So there will be no let off in our vigilance and attention to detail in these final rounds. We will be racing to win.”

Hamilton too, claims he will not be taking it easy as he looks to repeat his victory from 12 months ago.

"At the moment, I’m just focused on winning, clearly, and I’m enjoying driving more than ever," he said. "The challenge, the pressure’s intense. Just always want to elevate yourself and shine brighter each time you get in the car.

"There’s still three races to go. In my mind, I’ve still got a lot of points available. So I don’t think until it’s ever properly done and sealed you can ever get ahead of yourself."

Though the layout of the Autodromo Hermanos Rodriguez would seem to suit Mercedes, with a very long main straight and a fast, sweeping infield, one of the unique factors that teams have to consider could actually expose an ongoing weakness of the W08.

"It will not be easy to achieve this weekend in Mexico, this is an unusual circuit where the cars run at maximum downforce owing to the high altitude,” Wolff explained.

“Some of our most difficult weekends this season have come with the car running at maximum downforce, so we expect a tough and close-fought battle with both Ferrari and Red Bull. It will be important to be at the very top of our game if we want to get the job done.”

Valtteri Bottas would lead teammate Lewis Hamilton by almost half a second as Mercedes gained the early advantage by using the Ultrasoft tyre in Practice 1 at the Mexican Grand Prix.

With the most sets of Pirelli's softest compound at their disposal this weekend, the Silver Arrows would use them from the get-go with the Finn posting a 1:17.824s, almost a full second faster than the 2016 pole time as the greater grip of this year's cars proves more effective at the highest altitude circuit of the year.

The thinner air also negates some of Red Bull's power deficit and that allowed them to put both cars in front of the two Ferrari's as both teams ran the Supersoft tyres. Max Verstappen was third but would be unhappy with the setup of his RB13, ending his session some 20 minutes early to complete setup changes in time for Practice 2.

Daniel Ricciardo would be fourth as Sebastian Vettel and Kimi Raikkonen struggled under braking on the dusty surface at the Autodromo Hermanos Rodriguez, running wide at several corners and even spinning, in the case of the 2007 champion.

Sergio Perez's first goal of being best midfield driver at his home race began well in seventh for Force India, though fellow countryman Alfonso Celis, stepping in for Esteban Ocon for Practice 1,  would end his run in the wall after losing the rear at Turn 15 and causing a red flag.

Fernando Alonso will start at the back of the grid due to engine penalties but was eighth quickest in the morning session. McLaren teammate Stoffel Vandoorne will join the Spaniard with the same grid drop but saw his new Honda unit fail before he could set a time.

Felipe Massa was ninth with the two Renaults separated by just two-thousandths of a second in Nico Hulkenberg's favour over Carlos Sainz, meaning the German completed the top 10.

2018 hopefuls Antonio Giovinazzi and Charles Leclerc both made another Friday appearance with the Italian at Haas and the Monegasque F2 champion at Sauber.

Though the current Ferrari third driver would be two-tenths faster than the Academy member, the session could actually be considered a win for Leclerc as the gap between the two respective cars would normally expect to be larger.

Sean Gelael would also complete another Practice 1 outing with Toro Rosso, replacing the returning Pierre Gasly, and would be a tenth faster than the Kiwi following problems with the engine software on his car.

Overall a muted start to the weekend, dominated by a lack of grip despite the impressive times, with all teams on the same tyres and some proper race and qualifying runs to come in the afternoon, a clear picture will start to emerge.

Sergio Perez believes he will be allowed to race Esteban Ocon at this weekend's Mexican Grand Prix, claiming Force India will abandon the team orders it has imposed in recent races.

Relations between Perez and exciting new recruit Ocon have been tense throughout the year, with costly collisions in Azerbaijan and Belgium the flashpoints.

In the last two races, the Mexican has been instructed to remain behind his team-mate in a bid to avoid a repeat.

However, with a lucrative fourth place in the constructors' virtually in the bag, Perez is confident those restrictions will be eased.

"In Austin and in Japan, for example, we knew that the priority is to secure fourth place in the constructors’ which we’re very close to doing," he explained.

"So that’s the main priority. Then I think we have to gain the trust back, to show the bosses that we can race without any trouble. We should be able to race here.

"That’s the main priority I think here we can be quite strong actually."

The 27-year-old will be eyeing a headline result at his home race, and his hopes have been boosted by an upgrade package.

"We have a couple of upgrades on the car and the track should suit the car quite well, so definitely looking forward to finishing our very good season on a high."

Sebastian Vettel believes Ferrari is close to the battle building between Mercedes and Red Bull at the front, despite finishing fourth in Practice at the Mexican Grand Prix.

The German goes into the weekend needing a victory to have even a remote chance of keeping the Formula 1 championship alive and that also depends on leader Lewis Hamilton finishing outside the top five on Sunday.

Though it was thought the unique requirement of a high-downforce set-up for a high-speed circuit could favour the Scuderia, chances of that scenario playing out seem even harder to envisage for now as they struggled under braking and in the low-speed corners.

“We didn’t get a smooth session and the car was a bit so-so, some laps were really good, others were not so great,” he claimed. “In general, the car is quick but we need to work. I don’t think it’s an awful lot of work, it’s more about finding the balance."

Long runs too, were not where the four-time world champion wanted: “So-so,” again was his analysis. “I was stuck in a lot of traffic but I think it was the same for everyone. It’s a short track, all the cars on track, it’s always tricky. I think it was OK but we need to work.”

Vettel's afternoon was also interrupted by a strange incident when he reported a failure under his seat which resulted in a liquid spewing onto the seat inside the car.

“A fire extinguisher burst in the middle of the run,” he revealed. “Initially it was just burning and then turned out to be cold. The change cost some time, but we could recover at the end, as it’s a short track. It’s not ideal.”

The reason for the unique setup in Mexico City is altitude, with the Autodromo Hermanos Rodriguez the highest circuit above sea level on the calendar, with that comes challenges not seen elsewhere.

“It’s tough here to cool the car for everybody, so if you’re stuck behind someone, it’s a bit tough,” Vettel explained. “If you’re ahead, you can do your pace. Keeping the temperatures as low as possible will be tricky, whoever succeeds will have the edge.”

The fight for a seat alongside Lance Stroll at Williams in 2018 has taken another nasty turn with Felipe Massa offering blunt assessments of the two drivers most likely to replace him.

Former Grand Prix winner Robert Kubica and current team reserve driver Paul Di Resta both completed back-to-back tests at Silverstone and in Budapest between the Japanese and United States GP's with assessments of their respective performances described as solid and successful.

But the Brazilian has become increasingly harsh in his criticism initially claiming those at Williams who "know about motorsport" were backing him, to suggesting the team would be "much worse" if they did end their partnership.

Now the 37-year-old is taking aim at what he sees at the respective weaknesses of Kubica and Di Resta, beginning by questioning whether the Pole really would be physically up to the task of competing full-time in F1.

"I have no idea how he's driving, first of all," he said in an exclusive interview on Motorsport.com. "To be honest, I cannot do what he's doing, driving with only one hand and it's impossible for me to believe that he will not suffer with some of the races with this car that we're driving that is a lot more difficult physically.

"I really respect what he's doing, and what he's doing is just amazing but it's impossible to believe that he will not have some issues."

While at least trying to sound respectful towards Kubica, whose limitations in his right arm were suffered in a near-fatal rally crash in 2011, Massa maybe wasn't so kind about the former Force India driver who has been competing in DTM with Mercedes.

"I don't believe he's the right driver for the team, to develop the car and show the results and everything," he claimed. "Plus I mean I don't think he's doing a great job in what he's racing as well. Anyway, I'm not here to complain or say about anything, that's only my opinion."

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After those comments, however, Felipe insists there wouldn't be any hard feelings towards Williams if he was dropped, just a year after putting off retirement to allow Valtteri Bottas to join Mercedes.

"Yeah, sure, but I'm good on that. I have zero frustration," he said. "As I've said before, I did a lot more than I expected so if it needs to finish, it's the time. If it doesn't need to finish, it's because maybe something is still reserved.

"As I said, I'm quite relaxed, thinking about my job, thinking about my car. The time for being frustrated is passed already in my career."

Previously Massa had hoped for a decision by the Brazilian Grand Prix in just over two weeks, that would mean he could repeat the emotional farewell he thought he was saying last year at Interlagos if he was to leave, but it now seems Williams will not be ready until Abu Dhabi at the earliest as they continue evaluations.

Sebastian Vettel has backed Ferrari Team Principal Maurizio Arrivabene and praised his leadership qualities following reports the Italian team was considering replacing him at the end of the season.

The collapse of the Scuderia's championship challenge due to engine problems in Japan and Malaysia led to changes within the Maranello outfit with company Chairman Sergio Marchionne claiming failures in ensuring the quality of parts had led to the power unit issues.

Speculation began that Arrivabene was to be held responsible for those shortcomings and that current Chief Technical Officer Mattia Binotto would be drafted in, claims Marchionne would later squash.

"I don't think we need to overhaul the team. Both Mattia and Maurizio have been involved in this process," he said. "Picking one or the other is a bit idiotic. They were both at the table when the operation was going on and technically I'm involved too, I was the chairman. But that's not going to solve the issue.

"We need to win, that's the more important thing. I don't think it's attributable to a single guy. Processes may not have helped and those things are being addressed."

Ahead of the Mexican Grand Prix, Vettel also threw his full support behind his team boss and declared him one of the figureheads of Ferrari's recent turnaround.

"Absolutely," he said when asked if he had confidence in Arrivabene. "Look at the results. Look at where Ferrari was after 2014, how competitive Ferrari was in 2014 and the, I'm sorry to say, miserable shape it was [in].

"The spirit was down, I think he's the key person responsible for bringing most of that back, and to make the team grow, to open things up, to change things that have been set like that for, I don't know, 20 years before that, just because they used to be like that.

"I think he has a very innovative and creative way of thinking, so I think he's the right man. He's a very strong leader, he's well respected, I know he's well respected by all the people, no matter which level of the company, so absolutely I'm a fan."

Though the once very real aspirations of Vettel adding a fifth title and Ferrari claiming their first since 2007 have faded, with Mercedes already Constructors' Champions and Lewis Hamilton nine points away from securing the Drivers' crown, the German remains adamant his team is on their way to recapturing past glories.

"If you look at the results, it's coming," he said. "Obviously this year I would like it to be a bit different, especially towards the end, but these things happen.

"We're still growing, and we set ourselves the target at the very beginning, to grow and to do something new, something different – we're still on that journey. Expectation is always high; if you finish second in the championship, the year after you want to win, and you don't manage [to do it]...

"But I think where we've gone from 2015 to 2016, especially through 2016 and then for 2017, things are heading the right way."

Red Bull team boss Christian Horner has issued a warning to driver Daniel Ricciardo about considering his future with the Anglo-Austrian team, following comments by the Australian he wouldn't mind a future Mercedes seat.

Ricciardo's current contract with Red Bull expires at the end of 2018 and, after four disappointing seasons of coming up short, it is thought if the Milton Keynes factory fails to deliver again next season, the five-time Grand Prix winner will weigh up alternatives.

Another major factor he has to consider is the rise of current teammate Max Verstappen, who has seemingly become the bigger priority for the senior team as it was announced he signed up with the team until 2020.

Comments days prior to that from Horner, also suggested Verstappen should "build the team" around him going forward, raising some thoughts as to whether the Dutchman was now the preferred driver.

Those eyebrows were raised further when, last weekend in Austin, the 20-year-old received an engine upgrade which, it turns out, Ricciardo had no idea about until he was asked about it by the media.

"It is very difficult for us to measure what the difference is [between the two engine specs]," the Red Bull boss said as he defended not telling the Aussie.

"Renault have only made one engine available to each team and Max was due a change here. So obviously it made logical sense for that to go in his car this weekend and take the [grid] penalty.

"The intention with Daniel, and it is still the intention, is to not to have to take a penalty between now and the end of the season."

Nevertheless, with suspicions of growing backing towards Verstappen, any notion of that happening, which Ricciardo himself has played down, would go against one criterion which would put him off leaving.

"If I was to negotiate with another team, one of the first issues would be insisting on identical conditions,"  he said. "If someone said 'We'll sign you but you'd have to support your teammate', I wouldn't sign."

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But it is that warning of becoming a 'No. 2' at another team which Horner is using to try and convince the 28-year-old to stay.

“It’s an absolute priority for us to retain the drivers,” he told Sky F1. "Here, they have equal chance to go for that championship, if he goes to Mercedes or Ferrari he’s just going to be a number two driver.

“Daniel knows that we want to retain him in the team, and hopefully it won’t take too long to sort that out.”

It doesn't seem the driver is ready to "sort that out" just yet though, particularly after expressing a desire to test himself alongside the 2017 champion in waiting.

"Obviously I've had the chance with Seb and I've had it with Max," Ricciardo stated. "While Lewis [Hamilton] is in his prime I would like to challenge [him] and see [how I would do against him]."

With the Briton's current teammate Valtteri Bottas only signed on for one more year at the  Brackley team, that is an option which could open for him.

However, when asked directly if Mercedes would be interested, motorsport boss Toto Wolff replied: "We have just extended with Valtteri and we haven't thought beyond 2018."