An exhausted Lewis Hamilton wrestled his Mercedes to fifth place in the Japanese Grand Prix on Sunday and said the team faced their biggest Formula One development challenge in coming months.
The seven-time world champion, who has not won a race since 2021 and is now 38, said he was fighting hard for the team to finish second overall but major improvements had to come next season.
"It's tough on weekends like this, particularly when the car is such a handful," he said. "The car felt just the same as last year, it's bouncing and sliding."
Hamilton managed to finish ahead of Ferrari's Carlos Sainz but was beaten by the Italian team's Charles Leclerc and both McLarens. Team mate George Russell finished seventh.
He said Mercedes had taken the drivers' opinions on board.
"I think all the points that George and I give have been fully listened to," he told Sky Sports television at Suzuka.
"I have no idea where the car is going to be next year but we are a long, long way away.
"The next six months has to be the greatest six months of development that we've ever, ever had to close that gap, to be really banging on the door," said the Briton.
With Mercedes-powered McLaren finishing second and third with Lando Norris and Oscar Piastri, Hamilton said Mercedes needed to take a good look.
"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," he said.
"We've always been great at putting downforce on the car, it's just that with the way our car currently works, adding downforce isn't working -- it just makes it bounce more.
"Hopefully with the change in philosophy we will be back to where the team deserve because this is a world championship team," he added.