No Mercedes interference in title fight

Niki Lauda says Mercedes are letting Nico Rosberg and Lewis Hamilton fight freely for the 2016 title.

The German marque's drivers are the only two drivers still in the championship race, but Lauda insists one won't get preferential treatment over the other.

"I don't talk to them. They are free to race," he told the Brazilian broadcaster Sportv.

"They can do whatever they want," Lauda reiterated. "Leave them alone and just watch. And it's interesting to watch.

"Nico has a comfortable lead, but there should be rain on Sunday and problems can happen," he said at Interlagos. "In Formula One you can only be sure of a title after you've won it."

While Rosberg has repeatedly said the championship is not on his mind, team boss Toto Wolff feels he is taking a conservative approach.

"After Lewis retired in Malaysia, Nico knew he could finish second at every Grand Prix - and even a third - and still win the title in the end," Wolff told France's Le Figaro.

"It was therefore logical that - although he always wants to win - Nico takes a little less risk and manages this favourable situation.

"So it seems to be the most likely scenario that it will be decided in the last race, which I think will make Bernie very happy," he added.

And like Lauda, Wolff said Mercedes will ensure that the title is solely decided as the result of a clean fight between Rosberg and Hamilton.

"We are in the comfortable position of already winning the constructors' championship and we cannot lose the drivers' either," he said.

"Now, in this situation myself and the team need to be as neutral as possible not to favour one driver over the other. In Mexico, we even made sure both drivers had the same marketing and press times, so that one could not even complain that he is doing more," Wolff added.