McLaren will have a revised Honda engine this season as the former world champions seek to push their way back among Formula One's frontrunners.
"For 2017, the Honda engine architecture and layout have been altered to serve both for performance and packaging needs," McLaren technical director Tim Goss told the team website (www.mclaren.com).
"The new power unit takes much of the learning from the past two seasons, but has been specifically redesigned for this season."
McLaren finished sixth overall last season after a dismal 2015 in which they started a new partnership with Honda, after years of Mercedes power, and ended up ninth.
The most successful team after Ferrari, with eight constructors' titles and 12 drivers' championships, have not won a race since 2012.
The restrictions on engine development has been lifted, allowing Honda to overhaul a tightly-packaged 'size zero' design that has been plagued with reliability problems while Mercedes have dominated.
McLaren are the only team using the Japanese engines.
The new season will also feature far bigger tyres and revised aerodynamics, making the 2017 cars faster and with more aggressive looks.
"This season’s changes rank as some of the most significant we’ve ever had in the sport," said Goss.
"That’s likely to change the competition order -- because it’s such a big disturbance... but then what normally happens is that the best, and most well-equipped, teams tend to rise to the top again."
Goss said drivers expected the cars to be more challenging to drive and a knock-on effect would be that some corners would no longer be treated as corners because they could be taken without lifting from the accelerator.
"As the new cars will be going faster, some of 2016’s ‘corners’ will be classified as ‘straights’," he said.
"But because they (the drivers) will be going through them faster, they’ll be subjected to more G-forces -- and that’s still tiring on the body.