Mercedes chief Toto Wolff still misses 'irreplaceable' F1 legend Niki Lauda

Mercedes have created Formula 1 history this season by rolling what team boss Toto Wolff has described as “the double six”.

For Wolff, it is clear that while his team’s sixth successive constructors’ championship - secured at last weekend’s Japanese Grand Prix - carries significant meaning, it is undermined by a personal sadness.

Since his death in May, there has been no Niki Lauda by Wolff’s side. The Austrian has not been there to laugh with, to argue with and, most importantly of all, to be a friend.

Lauda, as non-executive chairman, and Wolff have been instrumental in creating the motorsport behemoth that is now the Mercedes Formula 1 team.

Crucially, it was the three-times world champion who persuaded Lewis Hamilton to quit McLaren towards the end of 2012. Lauda convinced the British driver it was Mercedes who would make him a multiple title winner rather than Red Bull, a team enjoying their own period of dominance at the time.

Since making the move, Hamilton has played a leading role in Mercedes’ dominance of the sport, finishing third in Suzuka while team-mate Valtteri Bottas took the chequered flag.

The result also meant only Hamilton or Bottas can now claim the drivers’ championship. “The double six” referred to by Wolff is an unprecedented feat in F1 - no team has previously won six successive team and drivers’ titles.

Reflecting on another successful season, talk inevitably switched to Lauda, without doubt one of the sport’s true heroes and legends.

A few months on, and Wolff is still missing a man renowned for his straight-talking, his dry sense of humour, and, of course, his trademark red cap.

“It is unbelievable,” said Wolff, his eyes lowering, almost as a mark of respect, as he begins to think and talk about Lauda.

“I feel it every day. I have moments where I think about him and it is surreal he is not here. So yeah, I miss him. It's easier to do this crazy schedule when you are two than alone.

"Most importantly I miss him as a friend, but also a sparring partner, someone to bounce ideas off, (easing the) pressure, keeping yourself honest. We were each other's release valve.

"But also different perspectives. If I saw things a certain way, he would say 'I disagree', and then we would have an argument. It was valuable."

Post-race in Japan, both Wolff and Hamilton dedicated the latest constructors’ success to Lauda, whose death has been the nadir of a season in which Mercedes have not had it all their own way.

That is despite starting the campaign with five consecutive, perhaps fortuitous, one-two finishes as Ferrari threatened but failed to take the chances that came their way. It has been a familiar trait this term.

At one stage in mid-season, it was Red Bull and Max Verstappen who took the fight to Mercedes. After the summer break, it was Ferrari and Charles Leclerc as the Scuderia finally got its act together.

Russia and Japan should also have yielded further Ferrari wins but the Italian team were conspirators in their own downfall. As a result, it was Mercedes who came away with the victories to wrap up title number six.

Wolff readily concedes his team “have not had the quickest package - car and engine” of late. At this stage, championship number seven may not be so easy to achieve next season.

“What we try to do is understand where we missed out and where we can improve,” said Wolff.

“These things happen for a reason and it reminds you to stay sharp. If you are not having all these bad days then you are not questioning yourself enough.”

There is also the rush of rising to a challenge. There is a satisfaction in being totally dominant, although the fighting spirit also relishes the challenge.

"It's very important to take yourself out of the bubble sometimes,” assessed Wolff.

"It's really nice to dominate every session and clock up the wins. But I had an interesting moment many months ago this year where somebody close to me, a friend of mine, said to me 'It's good that Ferrari is winning, Red Bull is winning', and I said to him 'What are you talking about?'

"He said that it's good for the sport, that we need variety, with hard racing.

"Fundamentally we love the challenge to rise and overcome difficult moments. It's part of that journey and it's enjoyable. It doesn't feel nice in those moments when you lose. But the buzz I feel in the factory is so positive after difficult weekends.

"Overall, for Formula 1, there needs to be more drivers and teams capable of winning, and we will do our utmost to stay on top."

For however many years Wolff remains with Mercedes, though, such a pursuit will be without Lauda.

As yet, Wolff concedes he is struggling to fill the void created by the loss of his close friend.

"I haven't replaced it properly, to be honest,” said Wolff. “He's irreplaceable in some way."