Lewis Hamilton believes as many as four teams could be in contention for the titles next season with McLaren being the new dark horse.
The Brit reckons his former team could become a threat now that they have ditched the Honda engines in favour of getting their power units supplied by Renault.
He is also expecting improvement from Ferrari and Red Bull, so he is aware that Mercedes need to start the season on the very top of their game.
"McLaren will have Renault engines, then we may see four teams fighting for the championship," Hamilton said via BBC Sport.
"Red Bull will be quicker (than this year) and Ferrari will be fast. We can't stand still. We have to keep moving forwards."
Hamilton added that his mentality is the same as it always has been and is only interested in finishing first.
He said: "I have the same mindset now for next year.
"When I'm training and preparing for a new season, I firmly believe that we can be contenders for the next championship.
"It may turn out to be not possible, but you have to have that mindset.
"If you go in with expectations of finishing fifth, it's not going to work. You've got to gear yourself up to win."
Hamilton is heading for the mountains in the off-season so he can recharge the batteries ahead of his latest title defence and fancies catching up on Game of Thrones in the process.
"I go to the same place in the mountains every year," he said. "I have my dogs, I'm in the snow, and it's very quiet and peaceful there.
"I spend most of the day sitting by the fireplace. We go skiing, watch some movies and catch up with some TV series.
"I've never even seen any of Game of Thrones. My friends and especially my brother are huge fans, and I think I'm going to get into it in the winter."