McLaren's 2018 car will be an "evolution" of the current one, according to team boss Eric Boullier.
Boullier told Brazil's Globo that although McLaren are switching from Honda to Renault power for 2018, the team are happy with their actual chassis.
"It has the least power, but we have one of the best cars in high speed corners," Boullier said.
So despite the forthcoming move to customer Renault power, he revealed: "We are not radically changing the car. The 2018 car will be a 100% evolution of the current car.
"The radiators required by the Renault unit are smaller than those of Honda, making our aerodynamic task easier," Boullier added.
"But I cannot tell you anything else."
Boullier also said that McLaren will enter 2018 with another healthy budget, even though former team supremo Ron Dennis said previously that the team must have works engine backing.
"[Bahrain's] Sheikh Al Khalifa and Mansour Ojjeh have a different vision," he said.
"They made a decision for the sporting side, so we should not have a smaller budget in 2018."
The 2017 season comes to a close with this weekend's Abu Dhabi Grand Prix, with McLaren on course to finish ninth in the constructors' championship.