Lewis Hamilton believes Mercedes needs the best six months of car development it has ever produced to have any hope of stopping Red Bull's dominance in 2024.
Red Bull secured a second straight constructors' title at the Japanese Grand Prix to cap what has been a record-breaking season.
The team has only failed to win at one of the 16 races so far.
Mercedes has been in the distant battle for best of the rest so far this year, although rivals McLaren were comfortably second fastest at Suzuka, where Lando Norris and Oscar Piastri secured Hamilton's former team a double podium.
Hamilton said Mercedes should look carefully at the huge gains McLaren has made this year for inspiration.
"I have no idea where the car's gonna be next year but we're a long long way away," Hamilton said after finishing fifth. "The next six months has to be the greatest six months of development we've ever, ever had, to close that gap and be banging on the door.
"The evidence is there with the McLarens and we can't turn a blind eye to that. We've got to look at what they've done and go in that direction. That is the direction. But I truly believe my team can do it. We've always been great at putting downforce on the car it's just that with the way our car currently works, adding downforce doesn't work, it just makes it bounce more."
At the start of the year, Mercedes confirmed it planned to abandon its original car development path after qualifying for the opening race in Bahrain.
With the team still learning about the new concept it introduced at the Monaco Grand Prix, Hamilton hopes better days are on the horizon.
"Hopefully with the change in philosophy we'll be back where the team deserves. Because this is a world championship team.
"We still are an amazing team. I have absolute faith in everyone, but the decisions made in this period of time are critical for our trajectory."
Hamilton has previously said Mercedes did not listen to his feedback on its original car concept when he raised concerns in 2022.
When asked if he felt the team was listening this time around, he said: "There are things that I've asked for that we've gone in a direction, part of the direction for next year. I think all the points that George and I give have been fully listened to."