McLaren boss Eric Boullier said the car that the team will use during the 2016 season is already better than the 2015 vehicle.
He said the racing fraternity could expect significant changes from his team next year, adding that the only element unlikely to be altered was the team's philosophy.
"Almost everything will change except the philosophy," Boullier told the AS newspaper.
"Right now, our new car for next year is already better than this (2015) one," added Boullier.
Equally optimistic about the coming season is Honda's Yasuhisa Arai, who confirmed that a completely new engine was being developed.
"As Eric says, our concept and philosophy remains but a completely new engine is being developed," said Arai.
Former World Champion Jenson Button already indicated earlier this week that he was more than satisfied with the developments within the team thus far, adding that he still wanted to be a part of the project at McLaren, despite the trials experienced in 2015.
"Hopefully next year we will be much higher on the grid because the whole package has improved," said Button.
"I think we need to improve the ICE (engine) and the deployment (energy recovery) but we also need to improve the car in general," added the British driver.
"It was not the fastest (chassis) on the grid," he explained.