As the ground-effect era draws to a close, Mark Hughes uses qualifying data and technical insight to explain why the Formula 1 field has converged - and why the reasons go far beyond the rules alone
The F1 grid converged more and more as the ground-effect era ended
With the 2025 Formula 1 season now over, bringing this four-year ground effect regulation set to an end, we can use one of the key metrics to assess the competitive field spread from the front of the grid to the back in that time.
Taken in isolation, the qualifying statistics tell a pretty compelling story of a steadily closing gap, with just one blip:
Season
Regulatory context
Qualifying field spread (front to back)
2021
Final year of previous regulations
3.21% (Mercedes to Haas)
2022
First year of ground-effect regulations
2.56% (Ferrari to Williams)
2023
Ground-effect regulations
1.46% (Red Bull to Alfa Romeo)
2024
Ground-effect regulations
1.76% (Red Bull to Sauber)
2025
Final year of ground-effect regulations
1.38% (McLaren to Alpine)
One of the key aims of these technical regulations was to narrow the field spread. Well, the field spread has definitely narrowed during that time as we can see from the chart. But was it because of the technical regulations in place during that time? Causation and correlation are not necessarily the same, after all.
Or was it because of the effect of the cost cap regulations (which came into force from ’21) and the Aerodynamic Testing Restrictions (ATR) whereby a sliding scale places more severe limits on simulation resources, the more successful you are?
Or was it because F1 has been more commercially successful in this time period than at any other time in its history and the franchise model, combined with the cost cap, has given the smallest teams the opportunity not to be resource-poor compared to the top ones?
The 2025 field was the closest it’s been in years
Grand Prix Photo
Was it simply because the longer the regulations are unchanged, the closer it inevitably becomes, as there’s a slowing of new knowledge for the top teams and some low-hanging fruit for the lower teams? If we look at the previous regulation set (from 2017-21), the gap narrows from 4.01% in ’17 to 3.21% in ’21 (and it did get down to 2.87% in 2020).
It’s probably a combination of all the above. But if there has been a technical element to it (as opposed to an economic one), it would probably be the way that these regulations have changed the previous differentiators between a fast car and a slow one. Because generating huge downforce from the underbody is relatively easy – but beyond that, more has not necessarily been better. So the chase changed from more to better, as the phenomenon of porpoising was encountered. A better balance between low speed and high, a better feeling for the driver, giving him the confidence to push harder, a better transition between entry and mid-corner which didn’t impose such big peak loads on the rear tyres. It was a more intricate chase of performance.
Red Bull initially solved it by having a rear suspension which allowed it to run relatively high and soft, with a suitably non-critical underbody design, with a domed ceiling for the tunnels at the choke point rather than the more angular designs elsewhere. That was the key to two seasons of Max Verstappen domination.
But by ’23, teams were beginning to figure out how to design floors with much better resistance to bouncing. These floors were immensely stiffer – and allowed the cars to be run ever-lower, where the really big – but previously unattainable – downforce was. Now the cars had to be run super-stiff at the rear, to keep them in that narrow window. This was where McLaren began to draw level and even edge away from Red Bull.
As F1 enters the final year of its ground effect era, teams are discovering that success now depends as much on intuition and adaptability as on traditional engineering precision, as Mark Hughes explains
By
Mark Hughes
Now the challenge, as the cars were running so stiff, was that the cars couldn’t be loaded up enough at the front into slow corners because the centre of pressure was not moving forwards enough. So the cars tended to have an underpowered front end in slow turns but overpowered on the entry to high-speed corners, where the cars became very nervous. The solution to that was more aeroelasticity of the front wings, so you could have the aggressive wing angle at low speeds but which would flatten out to be less powerful (relative to the rear) at high speeds.
Meantime, Red Bull had a car configured around the original concept and even though they too moved to stiffer and lower rears, the previous aero development had been around a different concept. So there was catching up to do. That came in the latter part of last year, with the Zandvoort and Monza updates.
The Red Bull was night and day better once it had received those updates. So that should be reflected in the numbers? Except it’s not. Its qualifying average was better only by 0.05% pre-to-post Zandvoort. The advantage of the updated car wasn’t so much in qualifying, where previously new tyre grip and Verstappen’s skill could mask shortfalls that became much more evident in the race. So the car won only two of the first 14 races (14%), won six of the remaining 10 (60%).
