Toto talks Championship victory for Lewis, the elite group of Champions he joins and doing the double
'He has been the differentiator'
It was a tough Mexican Grand Prix for Lewis and the team, but fourth place was enough for Lewis to wrap up the Drivers' Championship for the fifth time.
Nine victories, nine pole positions and 15 podiums so far... an impressive set of statistics from a remarkable season.
It's no surprise Toto believes Lewis has been driving at the top of his game this year.
"This is the best Lewis Hamilton that I have seen in the last six years," said Toto. "He has driven better, and he has been better out of the car. He was very complete. He has been the differentiator.
"We had times where the car was good enough to win, and then there were times where the car was not good enough to win and he was very stable.
"His race craft is great. That was always one of his strengths, but this year it was definitely one of the key factors."
'All great champions have these abilities'
Lewis now belongs to an elite group of three Formula One legends who have won at least five World Championships.
Only Juan Manuel Fangio and Michael Schumacher have claimed five Championships or more. So, what is it that distinguishes these exceptional talents?
"I think it is an ability to combine talent with hard work, intellect and emotional intelligence," Toto explained.
"All great Champions have all four of these abilities. If one is missing, you can still be a successful racing driver, but you are never going to achieve this greatness.
"One of his great character traits is that Lewis always concentrates on today. I think he has strong values that his life has taught him, and he sticks to those values even on difficult days."
For this reason, Toto is also convinced that Lewis will be pushing as hard as ever to end the year on a high: "Absolutely I don't think he wants to finish the 2018 season just holding on by his fingertips but to finish with good momentum."
'The job is not done yet'
There are still two rounds to go in Brazil and Abu Dhabi, and the team's full focus is now on claiming the Constructors' title.
"The job is not done yet," says Toto. "Obviously we are very happy about this fifth Drivers' Championship because that is the most visible and most important Championship. But there is a Constructors' Championship still out there that we want to secure and win, and it is not easy, as we were able to see today."
Ahead of the final two rounds, the team has a 55-point lead over Ferrari in the Constructors' Championship, with 86 points up for grabs.
"We have enjoyed the competition, and I also enjoy not being sure whether it is good enough what we are doing," Toto added. "The setbacks make the good days even sweeter."
Toto sees the 2018 season as the toughest we have had to contend with in recent years:"We won 19 out of the 21 races in 2016. That was nice and enjoyable, less stressful.
"But there is also the risk of complacency setting in. Then the regulations changed, and that really motivated us to be the first team to win a Championship after a rule change, and we did it. And this year was a gloves-off fight all year."
'He can go on for many more years'
Even after securing five Championship titles, four of them with Mercedes, Lewis is far from done, according to Toto: "I think if he is motivated and enjoys what he is doing, he can go on for many more years. As long as we can provide a car with which he can win a Championship and he continues to drive like he does, this can be a relationship forever.
"But the reason why he has won that fifth Championship is that he concentrates on the job in hand and doesn't look too far away. Because before reaching seven, there is a sixth to win, and we haven't scored a single point towards that one yet."
After winning five Drivers' Championships in a row, fans and the media inevitably draw comparisons with the Ferrari era of Michael Schumacher in the early 2000s.
However, Toto isn't getting carried away by that thought: "I think you can only count records once you close the book, and I don't see us closing the book at the moment.
"We enjoy what we do, and that is why I am not looking at this. I remember, when I was much younger, following Ferrari in the years they dominated in the 2000s. They were the benchmark for many years. We are on a similar trajectory, but we are not there yet. That's why these objectives keep motivating us."