McLaren MCL39

Development context

The MCL39 follows the MCL38, McLaren's first championship-winning Formula One car since 1998.^[2] Having won the Constructors' Championship in 2024, McLaren will be allowed only 70% the allocation of wind tunnel testing time baseline. Team principal Andrea Stella said he believed McLaren could overcome this disadvantage by improving efficiency elsewhere in the aerodynamic design process.^[3]

McLaren's success in developing a front wing that could flex significantly under aerodynamic load during the 2024 season was considered instrumental in overcoming Red Bull's dominance in the ground effect era.^[4] New restrictions to combat this use of wing flexibility were introduced, effective from the ninth race of the season (the Spanish Grand Prix).^[4] Stella said the team had planned for a "small adjustment" that would be implemented with the new restrictions, but denied they would negatively impact the team.^[5]

Initial design and development

McLaren Racing CEO Zak Brown said the team would take a "brave risk" approach to designing the MCL39.^[2] Engineering director Neil Houldey said McLaren would not compromise any of its 2025 development despite an entirely new set of technical regulations and engine formula being introduced in 2026.^[6] Stella said the team believed it had "maintained the rate of development" it had shown in 2023 and 2024 and that the MCL39 followed the same "linear trend" as the MCL60 and MCL38.^[7]

The MCL39 was the first McLaren car that lead designer Rob Marshall oversaw from its beginning.^[8] The car was a significant technical development over the MCL38, exhibiting substantial layout changes.^[8][9] The MCL39 appeared to have shifted its radiators further up and backward compared to the MCL38.^[7] It retained the front pullrod and rear pushrod suspension layout, but with increased anti-dive measures to better control the car's ride height.^[7][10] Other visible changes included new sidepod inlet shapes, revised engine cover bodywork, and a new, wider airbox inlet shape.^[8][10]

Stella said the team would deliver several early-season updates, consistent with McLaren's development plan in recent seasons.^[8][11]

Livery

The MCL39 used a one-off papaya orange and black geometric dazzle camouflage pattern for its pre-season filming day, as all teams had committed to launching their season liveries at a dedicated event.^[12][13]

The car's season livery was substantially identical to that of the MCL38.^[14] McLaren issued a statement explaining that the team had never changed its livery the season after a championship win and never substantially changed a livery during a period of sustained success.^[14]

Pre-season

McLaren were considered favourites to win a second consecutive World Constructors' Championship in 2025.^[15][16][8] Norris was the favourite to win the World Drivers' Championship,^[16][8] although Piastri also said he was a serious contender for the title.^[17] The MCL39 was first run on track in a private filming day at Silverstone in February 2025, driven by both Norris and Piastri.^[12] Stella stated that this version of the car was substantially the same as that which would be run in the official pre-season test.^[9][8]

During the test, Norris said the car handled similarly to its predecessor; he also said the rear end of the car was less stable than the team wanted.^[18][19] Other teams widely considered the MCL39 to have a performance advantage over the rest of the field.^[20][21][22]

Opening rounds

Norris qualified on pole and Piastri second for the season-opening Australian Grand Prix.^[23] The race was held in mixed conditions, and was interrupted by several safety car periods.^[24] Piastri lost second place to Max Verstappen of Red Bull Racing on the opening lap but regained the position later on and ran in second behind Norris.^[24] Shortly after switching to slick tyres as the track dried, both drivers went off at the same corner when rain returned.^[25] Although Norris managed to continue and pit to return to intermediate tyres, Piastri was stranded on a grass run-off.^[25] Piastri rejoined the race a lap down after slowly reversing off the grass.^[26] Norris won the race and set the fastest lap, and Piastri recovered to finish ninth.^[25] The result placed McLaren first in the World Constructors' Championship, and the drivers first and ninth in the World Drivers' Championship (WDC).

The Chinese Grand Prix was the first round of the season to use the sprint format. Piastri qualified for the sprint second,^[27] and Norris, who made an error in his final lap, qualified sixth.^[28] Piastri finished the sprint second.^[29] Norris made another error at the start, losing positions and finishing eighth.^[28] Piastri qualified on pole for the Grand Prix for the first time in his career and Norris qualified third.^[30] Piastri won the race and Norris – whose brakes began to fail in the closing laps of the race – finished second, moving Piastri up to fourth and allowing Norris to retain his lead in the WDC.^[31]

Norris qualified second and Piastri third for the Japanese Grand Prix,^[32] and they finished the race in those positions.