Champions McLaren will have "a completely new car" when Formula One returns from a five-week break at the Miami Grand Prix in May, according to team principal Andrea Stella.
Mercedes, who provide McLaren's engines, have won all three races so far this season but the last race in Japan was closer between the two teams.
Australian Oscar Piastri ended up second to Mercedes' Italian Kimi Antonelli at Suzuka and might have won but for a safety car period helping his rival.
"There was always the idea to deliver a completely new car, especially from an aerodynamic upgrades point of view, for the North American races," Stella told reporters at the team's factory.
"We could keep up with this plan. Obviously, the fact that the calendar has been changed sort of helped a little bit, like I'm sure (it) helped all the other teams that could work more streamlined towards upgrading the car rather than being busy with racing."
NO RACING IN APRIL DUE TO GULF CONFLICT
There has been no racing in April because the Bahrain and Saudi Arabian Grands Prix were called off due to the Iran war and its impact on the Gulf region.
That means Miami will be the fourth race of the season rather than the sixth.
"Across Miami and Canada we will see an entirely new MCL40 (car)... this is what I would expect of most of our competitors so it's not necessarily going to be a shift in the pecking order, it will be effectively just a check who has been able to add more performance within the same timeframe," said Stella.
The team are third in the standings, 89 points behind Mercedes who finished the first two races one-two.
McLaren, constructors' champions for the past two years and winners of the drivers' title last year with Lando Norris, are more limited than others on wind tunnel use and computational fluid dynamics (CFD) because each team's allocation is linked to where they finish each season.
However chief designer Rob Marshall told reporters that was not the big disadvantage it appeared to be.
"The truth of it is you have many potential developments that you want to run through CFD or the wind tunnel and some are good and some are bad," he said.
"So if you're bright and you approach it the right way and you think about stuff methodically... you just don't bother doing the stuff that wasn't worth doing and you carry on doing the stuff at the top of the list.
"So in a way you free up resources, because if you've got a lot of wind tunnel resources and CFD time, you end up doing a lot of stuff that's nice to have – but actually we're not in the business of nice to have. We're in the business of the stuff that actually works and so that's the stuff you do."