'Hunger' level will dictate Hamilton's exit from F1 - Häkkinen

Lewis Hamilton, Mercedes, Malaysian Grand Prix

The longevity of Lewis Hamilton's career in Formula 1 will depend on his ability to sustain his motivation, says two-time world champion Mika Häkkinen.

The Mercedes driver achieved his fourth title in 2017, and while there are no doubts about his presence in F 1 in the next couple of years, with a massive new contract likely just around the corner, many believe he could call it a day after 2019.

Häkkinen however reckons Hamilton will stretch his stay as long as he has the energy and motivation to fight on.

Häkkinen: 'F1 talent among the best I've ever seen'

"Lewis' achievement in winning four world championship titles is impressive, and you can see that he has kept the hunger alive, that is critical," Häkkinen wrote on his Unibet blog.

"When I won both my world championships in 1998 and 1999, I went into 2000 absolutely determined to win a third title, but it was not to be.

"After that year, when I felt my energy levels drop a little, it was not long before I retired."

Reflecting on the past season, Häkkinen admitted to have been mightily impressed by Max Verstappen, and the Finn also hopes Red Bull Racing will challenge more often for race wins in 2018.

"Max Verstappen was the standout driver of the season because he is so exciting to watch," he said.

"The two wins in Malaysia and Mexico showed that both he and the team have been getting stronger, and with Daniel Ricciardo winning in Baku, it means Ferrari and Mercedes could never relax."

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Phillip van Osten

Motor racing was a backdrop from the outset in Phillip van Osten's life. Born in Southern California, Phillip grew up with the sights and sounds of fast cars thanks to his father, Dick van Osten, an editor and writer for Auto Speed and Sport and Motor Trend. Phillip's passion for racing grew even more when his family moved to Europe and he became acquainted with the extraordinary world of Grand Prix racing. He was an early contributor to the monthly French F1i Magazine, often providing a historic or business perspective on Formula 1's affairs. In 2012, he co-authored along with fellow journalist Pierre Van Vliet the English-language adaptation of a limited edition book devoted to the great Belgian driver Jacky Ickx. He also authored "The American Legacy in Formula 1", a book which recounts the trials and tribulations of American drivers in Grand Prix racing. Phillip is also a commentator for Belgian broadcaster Be.TV for the US Indycar series.