Lewis Hamilton insists anything is possible in what have been labelled his three FA Cup finals in the closing month of F1s title battle. The Mercedes driver has vowed not to throw in the towel even though Rosberg could secure the title this weekend in Mexico. Hamiltons win in last Sundays US GP means he heads to Mexico with a reduced title deficit to Nico Rosberg of 26 points, but the gap remains sufficient for his Mercedes team-mate to be able to finish second in every race and become champion. Rosberg will also be crowned champion if he wins on Sunday and Hamilton fails to finish in the points. When is the Mexican GP on Sky F1?But, buoyed by his first victory in three months in Austin, Hamilton insists he has retained a positive mentality amid the ups and downs of recent months. Watch NOW TV Watch Sky Sports for just £6.99. No contract. Recounting his fluctuating fortunes since the summer break, Hamilton said: Spa went well [from the back of the grid]. I had the best pace in the weekend of Monza and then I didnt get the start, which kind of decided that. Singapore obviously wasnt great, then Malaysia was great and then it wasnt great [when his engine blew].So Ive still continued to keep a positive frame of mind - Ive got to. There are still points available, anything is possible. The moment you give up thats the moment youre doomed. Ive never given up in my life and I dont plan on doing so. Sky F1’s Martin Brundle sits down with Lewis Hamilton to discuss his ongoing battles with Nico Rosberg for the championship Hamiltons challenges in Mexico, Brazil and Abu Dhabi have been likened to three successive finals by Red Bull boss Christian Horner.Its simple for him - its like three FA Cup finals, said Horner. Hes just got to win all three races and then what happens with the other car he cant control.Although Hamilton has clinched two of his three world titles in final-race showdowns, the 31-year-old has not triumphed before when he has been behind in the standings at this stage of the season.Mercedes still wary of Hamilton-Rosberg volcanoIn 2014, Rosberg led the title race for much of the year, but Hamilton moved ahead with five races to go and never relinquished the points lead.Since F1s scoring system was changed six years ago, Sebastian Vettel in 2010 is the only driver to overturn a points deficit (14 points) with three rounds to go and win the title. The previous occasion came in 2007 when Ferraris Kimi Raikkonen came from 13 points back - the equivalent of 37 points today - to deny Hamilton, then at McLaren, the title in his debut year. Despite winning in Texas, Lewis Hamilton showed his concerns over reliability issues. Martin Brundle thinks hes trying to send a message to his Mercedes team Hamilton is not banking on history repeating itself in his favour this time, but is aware F1s past shows shows why he