GETTY Kimi Raikkonen and Lewis Hamilton are two of the grid's fastest drivers

Priestley worked intimately with all three men during nearly a decade as a mechanic at McLaren. One of the 41-year-old’s greatest regrets is never having been able to propel Raikkonen to an F1 World Drivers’ Championship and while the Finn does have, Priestley reckons he knows why Hamilton and Alonso both have more. "The two most complete drivers I’ve ever worked with are Lewis and Fernando,” Priestley told Express Sport ahead of the release of his book "The Mechanic: The Secret Life of the F1 Pit Lane", chronicling his years at McLaren. "I think they are the most rounded and complete drivers in that they are both incredibly fast and intelligent.

F1 2017 Drivers' World Championship standings Sun, November 26, 2017 Express Sport runs through the final F1 2017 Drivers' World Championship standings Play slideshow Getty Images 1 of 23 Click to reveal the F1 Drivers' Championship standings

“And Lewis now has become so experienced and rounded when he’s in the racing car that you will struggle to find anybody better than him. “Kimi was one of the fastest but he was never the most complete. “There were things that Kimi do, lengths he didn’t go to that Lewis and Fernando both do. It’s the extracurricular stuff: the practice, the preparation, the simulator work. If you’re looking for a weakness in Kimi, it’s that. “With Lewis, he does all of those things and he’s also a massive ambassador for the sport.”

GETTY Marc Priestley believes Kimi Raikkonen is a faster driver but that Lewis Hamilton is more dedicated

But the 2007 season, when Priestley was able to work with both Alonso and Hamilton in the same team, ended in disaster: McLaren’s Constructors’ title was stripped after it emerged they had secretly obtained data about the Ferrari car while neither driver won individual honours as a result of a series of clashes on and off the track that saw the Spaniard quit the team after just one year. “That year when we had by far the best car, by far the two best drivers in the world and both championships should have been ours,” Priestley added. “They were there for the taking and in the end we missed out on them both. If there is ever a regret, it’s that. “We threw away two championships that year for a number of different reasons.