In his first year with Mercedes, Lewis Hamilton's relationship with girlfriend Nicole Scherzinger was a dominant factor in his on-track performance, says former McLaren man Marc Priestley.
Hamilton is on the verge of securing his fourth world title this weekend, his third with Mercedes. But Priestley, who was a mechanic at McLaren during the British driver's year at the Woking-based team, reveals in a new book that Ham's love life often had a direct impact on his results.
"Lewis’ weakness is an emotional one rather than anything to do with his driving ability," Priestley told Express Sport ahead of the release of 'The Mechanic: The Secret Life of the F1 Pit Lane'.
"As an example, when he was going out with Nicole Scherzinger, the stuff that was going on in his private life undoubtedly affected his performance in the race car.
"Those two had a very on-off relationship at times, particularly after he left McLaren and went to Mercedes.
"Lots of my colleagues and friends [at Mercedes] said to me in those first few years at Mercedes it felt like there was more effort being put into keeping Lewis and Nicole together than anything with the car because when Lewis was happy in his personal life, he was focused and on top form"
"You saw results off the back of that. So when Lewis and Nicole had a very public falling-out or they were off at that moment, you can quite clearly trace those moments to terrible weekends in a Formula 1 car."
Priestley also suggested that Hamilton's split in 2010 with his father Anthony, who had been managing his career up to then, also affected his driving.
"When he was having issues with his Dad, his performance dropped away," Priestly added.
"So if you’re looking for a weakness in Lewis, it’s probably that. That’s why we love him of course. He wears his heart on his sleeve and you get emotion from him. That can be good and bad."
"The emotion can be great when for example after a tough season last year, he comes back stronger this," he added.
"He will use those negatives and turn them into positives.
"But when he’s having a difficult time in his personal life, he finds it much harder to turn those into positives when he gets into a race car."
Gallery: The beautiful wives and girlfriends of F1 drivers
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