How the MCL39 became McLaren’s next great F1 car

Forging a path to the top of any premier-level sporting discipline is an immensely perilous journey, one festooned with setbacks, self-doubt, and sacrifice. Staying there? That’s an arguably greater challenge, one that requires a subtly different skillset. 

McLaren made the precipitous climb from the back of the field to the summit of Formula 1 through 2023 and 2024, and was ultimately rewarded with its surge to a first constructors’ crown in 26 years. 

This rise has been underpinned by its not-insignificant reshuffle of staff, as Andrea Stella sought to put his own stamp on the squad after taking over as team principal. While Stella sought to course-correct the team’s fortunes, the troubled MCL60 of 2023 was transformed into a frequent podium finisher.

Subsequently, the MCL38 of 2024 racked up wins through the year and ultimately contributed to that title success in the teams’ championship. 

To continue weaving further success into McLaren’s lengthy tapestry, the MCL39 had to move the game on significantly. The stagnant regulations and ongoing convergence throughout the field made this an ambitious aim.

The field had compressed across the course of 2024; hundredths, not tenths, decided positions. To circumvent the variance, Woking’s engineers wanted to chase the holy grail of car design: build a machine that could reduce the effect of F1’s myriad variables through a surplus of superior performance. 

McLaren managed to move the game on significantly with the MCL39 during period of convergence

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For the most part, McLaren has done so, leading to its smothering of the constructors’ championship – wrapped up in a pretty bow with six rounds still left to go. Lando Norris and Oscar Piastri continue to spar for supremacy in the drivers’ championship, accosted by Red Bull’s four-time title winner Max Verstappen. 

While the might of the MCL39 has dwindled towards the end of the year, not helped by the early wrap-up of its development cycle, that shouldn’t take the shine off the car’s quality throughout 2025, especially in the nascent stages of the season.

It’s also had its quirks, some of which have proven to be a source of occasional fury for both drivers – but once the car enters ‘the window’, it’s been dynamite. But what makes this papaya projectile tick?  

While McLaren had been hard at work refreshing contracts for its key staff, including head of aerodynamics Peter Prodromou, the MCL39 was the first car to have chief designer Rob Marshall involved from the outset

Willingness to innovate – even with 2026 on the horizon

With F1’s all-new 2026 regulations looming larger on the agenda, teams were ultimately more likely to prioritise evolution over revolution for this season. Rather than exhaust resources on getting a brand-new car concept bedded in, opting for a continuation of a proven model generally requires less developmental attention. 

That doesn’t mean a team can’t innovate within the existing framework, something that McLaren has proven with its MCL39. While McLaren had been hard at work refreshing contracts for its key staff, including head of aerodynamics Peter Prodromou, the MCL39 was the first car to have chief designer Rob Marshall involved from the outset.

Marshall’s design team had been tasked with the car layout for 2025 – and, beyond, for 2026 – to get more out of the McLaren package. So, while many of the visual cues were familiar when compared to last year’s car, there were some key points of interest to observe when scratching under the surface. 

Early struggles in the 2023 season were eased as the MCL60 was turned into a frequent podium finisher

Photo by: Andy Hone/LAT Images via Getty Images

For one, the overhauled front suspension demonstrated the lengths that the team would go to, particularly in its aim of creating more consistent downforce from the car’s underbody. The upper wishbone had its rear leg positioned further down, hinting at a more extreme approach to generating an anti-dive effect to keep the floor at a consistent level throughout a lap of any given circuit. 

At the rear, McLaren also spent much of its development time enhancing the flow-field conditions within the braking system and around the tyres. Over 2024, McLaren had found a growing niche in building tyre deltas through race stints, an effect that snowballed into situations where the two drivers often burst into life later into the races.

If it could continue to do that organically, it had a mechanism that could ensure tyres would not overheat at the end of a qualifying lap and could mitigate thermal degradation during a race.  

There was another aspect to the MCL39 that perhaps was not as well-documented until later into the season, oddly characterised by the point of greatest plank wear. Most teams had started to experiment with adding anti-lift characteristics into their rear suspension, with the aim of stopping the rear end from bouncing quite as much under load and over bumps.  

Most teams experience their greatest level of plank wear at the rear, which has largely restricted how low the diffuser area can be situated towards the ground. With an anti-lift format at the rear this can be kept relatively static, but McLaren has found even more success here by running its suspension in a manner where the plank wear shifts forwards, allowing it to keep the rear end much lower to the ground, and increasing the effectiveness of the diffuser. 

It’s said that, since F1 cars have very little spring travel (or torsional resistance) left to play with at high downforce, it all lies in the flex of the suspension members themselves. Evidently, McLaren had been able to give itself a bit more leeway at the front to allow the plank to drop first, while simultaneously mitigating front-end dive under braking.  

Challenge to Red Bull was stepped up again in 2024, resulting in six GP victories and the constructors’ crown

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Early season success – but ‘numb’ front end creates difficulties

Interestingly, the early main concern about the MCL39 pertained to the rear end, not the front. While it had emerged in testing that McLaren was very strong over a race distance, the drivers had found it a little bit livelier than expected when hustling the car around for a qualifying lap.

“I think if we want to improve anything at the minute, it’s still the rear of the car,” Norris said during the pre-season test in Bahrain. “The more you can improve the rear, the more everything just gets better. But the rest of it feels correct and it feels like it’s in the same ballpark [as last year]. That’s what we want. I don’t think we’re expecting to be a big step ahead of anyone.” 

In his exclusive interview with Autosport (October 2025 issue), Piastri concurred with Norris’s earlier comments about the launch-spec McLaren: “The car was very tricky to drive on the limit in testing. And, you know, our race runs were always very strong, but in the kind of qualifying sims we were genuinely struggling. We had a lot of work to do to try and unlock that.” 

Piastri found the turn-in of the car relatively agreeable, while Norris stated that the car “does not suit the way I want to drive in an attacking way”

Qualifying performance has been spottier compared to McLaren’s prowess in race trim, although both drivers have been capable of turning multiple pole-winning laps out of the MCL39. It’s just a little bit more difficult to do, and that’s demonstrated in the way that the car likes to be driven. 

Both Norris and Piastri concurred that it was not worlds away from how the 2024 car operated but, when at the front of the field, those characteristics are somewhat heightened. Once the team had got the rear to settle down after testing, the point of difference between the two drivers shifted to the front end. 

At the start of the year, Piastri found the turn-in of the car relatively agreeable, while Norris stated that the car “does not suit the way I want to drive in an attacking way. It doesn’t suit me in terms of me wanting to push the entries and push the braking.”

MCL39’s primacy made clear by McLaren tying up this season’s constructors’ title with six rounds to go

Photo by: Mark Sutton / Formula 1 via Getty Images

That’s evident when looking at available GPS data, where the two McLaren drivers tend to brake sooner for corners, let the front end bite, and then hit the throttle earlier out of the corners. While early turn-in speed is sacrificed, the corner exits can be exploited a little bit more. 

Those characteristics can go some way towards explaining the difference between the two drivers in the early season. Piastri thrived and motored off into the championship lead, while Norris found the car much more difficult to contend with over a single lap once he’d stepped up to the oche in qualifying. In race trim, those characteristics were more muted, but the race permutations during 2025 have largely hinged on qualifying performance. 

That’s not to say Piastri didn’t find it occasionally tricky to work with; Stella noted that both drivers felt that the front end could be “numb” in offering driver feedback, making it difficult to respond to the car in real time. Stella explained the phenomenon during the Miami Grand Prix weekend, when reflecting on how Piastri missed out on pole versus Verstappen. 

“We can produce really good corners, but it’s difficult to be repeatable for our drivers,” he offered. “Oscar made a comment. He said after his Q2 lap, ‘Turn 1 was so good, but I’m not sure I’m going to be able to repeat, because I’m not sure exactly how I made it – the car didn’t give me a great feeling as to how this was happening.’

“It’s a car that doesn’t give you much cueing, which is the technical word we use. And this means that it’s not easy for our drivers to repeat some big performances that we can see in individual laps.” 

When Norris seemed at sea with the car, McLaren took some of the feedback and implemented a revised front suspension package for June’s Canadian Grand Prix. This was optional for the two drivers and did not yield any immediate performance changes, but the idea behind it was to enhance the more visceral cues for the driver.

Stella noted one of the MCL39’s flaws was a front-end ‘numbness’ reported by both drivers

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It was a small geometrical change to the overall caster angle, which in turn produces a change in kingpin inclination (the angle between upper and lower suspension joints, but viewed front-on). 

This induces more self-aligning torque associated with the wheels while the driver steers, something that offers greater feedback. It wasn’t quite a panacea for the MCL39’s weak points, but it at least gave Norris more confidence with the car; Piastri, meanwhile, felt he didn’t need it. 

Balance and counter-balance

As in 2024, McLaren produced a series of beam wing options throughout the early season to give it more choices when balancing the car out. One of the tricks that F1 engineers have picked up has been in reworking the front wing elements to draw more performance out of the underbody, which in turn has required the teams to implement more options at the rear to balance out the downforce levels. 

Stella believes that, even if McLaren had continued to develop the car for a few more weeks, it would only find the most marginal of gains. His assertion was that McLaren had entered the season with a car that was “already quite mature”

McLaren has tended to operate with a split beam-wing design, with a lower single element used to mount the wing to the gearbox, and the second wing elements mounted higher up and sculpted around the exhaust. These upper elements tend to be situated at a lower angle of attack, yielding a small amount of downforce while helping to link the low-pressure flow fields behind the car to keep the floor working effectively.

Along with the front suspension modifications for the Canadian GP, McLaren also introduced a revised front wing with more furniture situated on the element-to-endplate mountings. This was one of the developments that got McLaren’s typically studious treatment: trialled in Montreal practice, left unraced, and then dissected in the analysis before being implemented properly for the Austrian GP weekend next time out. 

The team also made additions to its floor throughout the first half of the season to remain competitive; Norris had warned early in the year that McLaren still could not afford to take its foot off the gas too soon. But, with 2026 requiring plenty of lead-up time, it was only a matter of time before McLaren diverted its resources away from the MCL39.  

McLaren’s 1-2 in March’s Chinese Grand Prix symptomatic of its early 2025 domination

Photo by: Mark Sutton / Formula 1 via Getty Images

Should McLaren fail to secure a first drivers’ title for either Norris or Piastri, it could be accused of closing out development on the MCL39 too soon, though it’s fair to say that the odd driver error and occasional sub-optimal strategy has cost the car wins.

Red Bull, in its determination to understand why its RB21 had initially proved so inconsistent, continued to apply updates to the car after the summer break. The gains in performance that the team has uncovered suggest that it was right to do so, and the rebirth of Verstappen’s title defence has started to put both McLaren drivers under scrutiny. 

Stella believes that, even if McLaren had continued to develop the car for a few more weeks, it would only find the most marginal of gains. His assertion was that McLaren had entered the season with a car that was “already quite mature”, and that even the mid-season updates had not offered any dramatic improvements – according to his comments, the car had reached a plateau. 

He also added that, since the aerodynamic testing regulations hurt the championship-winning team the most, it’s much more difficult to straddle two seasons and balance the resources for each. 

“It takes weeks for us to add one point of aerodynamic efficiency because we were at a plateau in our aerodynamic development,” Stella explained over the Mexican GP weekend. “In the 2026 car, every week we add a lot of downforce. So that’s where, with the best information you have available, you have to make a call.  

“We also don’t have to forget that by being the champions, we are the most restricted by the regulations in terms of the wind tunnel and CFD allowance. It’s not like we have an unlimited amount of resources that we can use. We need to be considerate in the way we allocate resources this year to next year, because it comes from the same pot when it comes to CFD and aerodynamic wind tunnel testing. 

McLaren suspension shifts plank wear forwards, allowing the rear to be run closer to the ground

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“It’s not like if I spend three weeks more on the 2025, I’m going to add one tenth of lap time. We had plateaued. To produce the upgrades that we took to the middle of the season, it was a huge undertaking.

“We were like, ‘Should we actually finalise?’ We were struggling to improve what was already a pretty mature project. And you have seen how many cars actually attempted to develop and sometimes things were the opposite direction.” 

The legacy of the MCL39

It’s admittedly difficult to look objectively at the potential legacy of a car as a whole, at least while the season is still ongoing. Recent results have been contextualised by Red Bull’s reinvigorated fortunes, and that team’s dominance with its RB19 back in 2023 has perhaps skewed perceptions of what McLaren should have been able to achieve. 

The MCL39 should, in time, be as revered – and if one of its drivers can close out the drivers’ title, it may command a higher pedestal in the pantheon of great F1 cars

What is impressive, however, is how McLaren has been able to enjoy a semblance of consistency in a year where the field is much more compact.

The overall supertimes – supertimes are based on the fastest single lap by each car at each race weekend, expressed as a percentage of the fastest single lap overall (100.000%) and averaged over the season – from the four seasons in this era correlate with that: the 2022 field was separated by 2.396% from the fastest car to the slowest; 2023 was lower at 1.584%; 2024 had a 1.698% difference; while 2025 currently stands at a 1.397% difference between the top and bottom teams on average after Mexico. 

That Red Bull has managed to break into winning contention and put up a drivers’ title contender is, in some ways, reminiscent of McLaren’s season in 1998. That year, the MP4-13 was the class of the field, but the might of Ferrari and Michael Schumacher remained a pervasive thorn in its side throughout the duration of the season – up until the final round of the championship. 

New front wing tried out in Canadian GP practice, then assessed in detail, and raced in Austria

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It’s a similar story to 2007, where the McLaren MP4-22 was arguably a faster car than that year’s Ferrari, but the repercussions of the spy scandal and two drivers taking points away from each other ensured that Ferrari won both titles. 

Yet, history decrees that these were both great cars. The MCL39 should, in time, be as revered – and if one of its drivers can close out the drivers’ title, it may command a higher pedestal in the pantheon of great F1 cars.  

After all, it gathered an advantage over a once-dominant Red Bull in a relatively static ruleset, where progression has largely diminished throughout the field. The engineers behind that turnaround, led by Prodromou, Marshall, Neil Houldey and Mark Temple, are worthy of the plaudits.

This article is one of many in the monthly Autosport magazine. For more premium content, take a look at the December 2025 issue and subscribe today. 

The MCL39 is the first McLaren to have chief designer Marshall involved from the inception

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