Tuesday's Formula 1 news roundup: Sebastian Vettel, Helmut Marko, Lewis Hamilton

Sports Mole rounds up all of the latest news regarding Formula 1 on Tuesday, December 17.

Tuesday morning's headlines:

Rivals don't return Xmas cards - Vettel Sebastian Vettel says F1's top drivers don't respond to his Christmas greetings. Read more.

No 25-race F1 calendars yet - Todt Jean Todt thinks Formula 1 needs to lift the throttle when it comes to expanding the annual calendar. Read more.

Team boss role 'less fun' without Lauda - Wolff Toto Wolff has played down persistent speculation that he is first in line to succeed Chase Carey as F1's CEO. Read more.

FIA tests proved Ferrari engine legal - Binotto Mattia Binotto says the flurry of late-season technical directives and checks demonstrated that Ferrari's 2019 power unit was legal. Read more.

Valentino Rossi eyes four-wheel switch MotoGP legend Valentino Rossi says he sees the next phase of his career on four wheels rather than two. Read more.

Vettel struggling politically at Ferrari - Marko Dr Helmut Marko thinks former Red Bull champion Sebastian Vettel is struggling politically at Ferrari. Read more.