F1 2020 Rules

The Formula 1 technical and sporting regulations for the 2021 season, announced at the Austin Grand Prix, represent the most significant changes to the sport’s governance in decades. Liberty Media and the FIA hope that the new rules will revolutionise competition both on and off track.

Trying to improve overtaking in F1 is hardly a fresh idea. You only need look back to 2009, when new regulations, resulting from the findings of the Overtaking Working Group, were supposed to slash downforce and close the field up.

Most teams had nearly matched their 2008 downforce figures before the season even started, and Ross Brawn, then the man in charge of Honda’s factory effort, had pointed this out to regulators well in advance. The problem was a lack of technical firepower on the rule makers’ part, and the resulting regulations were riddled with loopholes, which teams exploited to the hilt.

Liberty and its FIA counterparts were determined not to make the same mistakes. Development of the new regulations has been characterised by an unprecedented level of research and development, looking specifically at reducing the performance loss suffered by one car following another.

A group of technical experts was assembled with Ross Brawn at the helm, a man whose engineering and management skills need no introduction. Pat Symonds was also enlisted while Nikolas Tombazis, former chief designer at Ferrari, headed the FIA’s contribution. The whole operation came under the title of the Aero Working Group.

Rather than taking informed guesses and hoping things worked out, the new rules were to be developed through methodical analysis and testing, making extensive use of CFD (computational fluid dynamics) and other simulation tools as well as wind tunnel tests. The teams’ resources were also utilised. 

The AWG’s starting point was to ascertain how a current car behaves aerodynamically, using the design assets of the defunct Manor team. F1 purchased the design of Manor’s 2017 car when the team folded, including the wind tunnel model, giving it an accurate representation of a then-current car.

Analysis of this car allowed the exact aerodynamic mechanisms which create such difficult following-car conditions to be pinpointed. Brawn and Co knew the primary problem was the wake of air generated by a leading car. The research, which first sought to establish the accuracy of their simulated car’s wake and then looked at its impact on a following car, gave clarity as to the areas that generated the most disturbance.  Although an F1 car has a plethora of complex aero appendages, there are a few key parts that produce the bulk of downforce: the front and rear wings, the front edge of the floor and the rear diffuser. Almost every other part is there to condition the flow over these to make them perform as well as possible (maximum downforce for minimum drag).

The front floor, and further downstream the rear wing and diffuser, are driven by the flow coming off the central section of the front wing (often referred to as the Y250 vortex), which is fettled and refined by the many small turning vanes and other devices under the nose and in the barge board area, steering it either under the car or around the sidepods.

To keep these flows tidy, aerodynamicists do everything possible to push the messy wake from the front wheels outboard, rather than letting them get sucked inboard. This outboard wake was identified as the main culprit in disrupting flow over a following car.

Once the rules development team was happy that the results seen in CFD were an acceptable representation of reality, a concept model was designed that aimed to prevent the problems. Development and refinement of this model took place through the end of 2018 and into 2019, using input from the teams to assess its performance and also suggest alternative design solutions.

According to the AWG simulations, a 2019 car loses around 45 per cent of its downforce when following one car length behind another, and even five car lengths away concedes 30 per cent of its aero performance. The final iteration of the 2021 concept showed a loss of just 14 per cent when directly behind and minimal losses at greater distances.

An impressive result and one that should translate relatively well into reality. However, locking down areas of car design that really matter will still be a defining factor.

Engineers within the paddock were, by and large, impressed with the research. Speaking earlier in 2019, before the rules were officially unveiled, Racing Point technical director Andy Green said: “This is the first set of work I have seen [from F1] that has gone into so much detail on the following car, with a real focus on what is actually happening and how you go about mitigating the losses to the car behind. It looks like a great piece of work and is unprecedented.”

Key changes explained


The 2021 rules will demand a near total reset of teams’ designs. For the last three decades aero development has been an evolutionary process, optimising the front and rear wings, a flat floor and diffuser.

In ’21, the cars will move to a ground effect concept, with underfloor tunnels developing the lion’s share of downforce (although a front and rear wing are still needed). Rather than pushing a wake to the side, the rules seek to drive the majority of it under the car or over the rear wing, ejecting it in a tall ‘mushroom’ at the rear, clear of a following car.

Coupled to this concept, most of the small aero adornments, that Mercedes’ James Allison has referred to as ‘aero porn’, are gone. The new cars will have a much cleaner aerodynamic profile; all of the small flicks and vanes were deemed to be part of the messy wake problem. Allowing their proliferation on the new cars would provide too much opportunity to corrupt the concept.

Bargeboards will also vanish, but there will be some scope for teams to develop the shape of the inlet to the underfloor area. There will also be freedom around the nose, the number of front wing elements, the rear wing supports and areas such as the roll hoop.

The tightest controls are reserved for the space around the front wheels, incorporating the front wing, brake ducts and the brake ‘drum’ housing that sits inside the wheel. The latter will be a spec part, deemed too sensitive to the overall aero concept for teams to be allowed to alter, while the brake duct and wing have a much-simplified form, with geometric constraints that should stop aerodynamicists steering the air outboard.

A representation of the changed wake air flow
A representation of the changed wake air flow

Overall, and beyond the big-picture concept change to ground effect, the main visible impact of the new rules will be far fewer aero flourishes on the cars. Unless the rule makers have really slipped up, there will be no surprise aero add-ons appearing in the way, for example, T-wings did.

Aero development is going to be about massaging the surfaces of the car. Ben Agathangelou, head of aerodynamics at Haas, says: “That will force the hand of aerodynamicists to focus much more on macro surface evolution, rather like we do with the [2019] front wings we have now as opposed to just bolting parts on.”

Ultimately, aerodynamicists are well versed in working the air to their benefit; there will be a learning curve, but they will find ways to gain performance just as they always have done. New caps on CFD and wind tunnel usage will make finding these gains trickier, but it will not be insurmountable.

Pros: The new aero rules will, in theory, create more ‘raceable’ cars, while the constraints on testing coupled to the budget cap should reduce the disparity between the haves and have-nots. 

Cons: Less engineering freedom, which many argue is part of F1’s DNA – any strokes of aerodynamic genius will likely be less obvious to fans. The better resourced teams will still find ways to chase a greater number of development avenues.

Power units

The power units will remain relatively untouched from their current form. However, there will be an imposition of some spec components, particularly in the fuel system; for example, the high-pressure fuel pump and associated parts. The rule-makers’ reasoning is that preventing development of the fuel system should make circumventing the rules around fuel flow even harder than it already is, while also reducing costs. This may affect some engine suppliers more than others, as the combustion systems in the modern hybrid engines are so refined that even very subtle changes can have an effect on performance.

There are some additional stipulations around the use of ‘exotic’ materials in the power units, but many of these are simply evolutions of the current rules, an example being a requirement for any materials used to be commercially available (although the wording appears to exempt any proprietary materials already in use prior to 2019).

It is a change in the sporting regs that will likely have the greatest impact on the power unit development race. For the first time, there will be a cap on dyno testing time as well as constraints on the type of equipment used. Currently, engine manufacturers can run as many development engines or MGUs as they like, allowing them to try out many different ideas simultaneously. Capping dyno time and the number of dynos in use will curtail this activity to a degree.

As evidence of the bartering process between the teams, Liberty Media and the FIA, the rules stepped back from a previous proposal to use a spec transmission system across the field. Instead, constraints will be placed on the minimum size and weight of the transmissions and teams will only be allowed one update in a five-year period from 2021, the intent being to remove the gearbox as a performance differentiator.

Pros: The move to spec parts in some areas and the limitations on development should reduce costs for customer teams.

Cons: As development of the power units begins to plateau, gains will become harder to find; manufacturers will still invest the same resource for lesser returns.


The most visible change for 2021 will be a switch to 18-inch wheels, a long talked-about shift. This will alter the way engineers have to manage the detail of a car’s suspension design, as the tyres (which act as an undamped spring) will have a lower profile. Meanwhile, there will be a significant simplification of the components used, with brake systems, suspension parts and other ancillaries all subject to tighter control.

For example, some teams currently use complex systems of hydraulic springs, interlinked dampers and devices such as inerters to help control the attitude of the car; a vital aspect of maximising aerodynamic performance. In 2021 these will be effectively banned, the rules explicitly stating that only traditional springs and dampers will be allowed, with their function being closely monitored. Therefore many of the tools chassis dynamicists and aerodynamicists use to control the car will be lost.

There will also be tighter constraints on using the suspension members, such as the wishbones and pushrods, to influence aerodynamics. As an example, the outboard suspension mounts will have to sit within the volume of the wheel rim, rather than outside. This will outlaw some of the current setups, where the upper wishbone mounts sit very high (for example, on the Mercedes W10) and limit the scope for clever placement of the suspension arms for aerodynamic gain.

Pros: The simplification of suspension should reduce cost and could lead to less control over setup. This may create greater unpredictability in performance between teams from race to race. 

Cons: The reduced number of setup tools in teams’ engineering arsenals will make it harder to work around potential flaws in their car designs – for example, underworking or overworking the tyres.

The key players behind the rules revolution
The key players behind the rules revolution

Breaking the rules

For teams’ engineers (and despite PR announcements that may say the contrary) their sole intent will be to bend the new rules and maximise performance. That is their job and it would be a challenge to find any engineer in the paddock willing to say with a straight face they develop with equal competition between cars as their goal.

Those running the sport accept that this is the reality of competition and to be fair, the teams (particularly the big players) have made some significant compromises regarding the size of their collective creative playpen. In the development of the new rules, Liberty and the FIA have gone to great lengths to try and limit the sheer engineering level that Ferrari, Red Bull, Mercedes et al have to subvert the intent of the regulations. 

The most important aspect here is that the aerodynamic concept only works in conjunction with new methods incorporated within the rules for defining bodywork dimensions. Previously, the majority of bodywork was dictated by square bounding boxes, within which parts had to fit.

Under the 2021 rules, the regulations prescribe much tighter constraints on both the size and the shape of parts, based on a new coordinate system and verified at the track using optical scanners to compare the real car to CAD data. Add in the use of spec parts in key areas and the hope is, while not watertight, that the main wake-influencing features will be unbreakable.

Additionally, the sporting regulations now incorporate mechanisms to allow easier alteration of the rules if someone does find a gaping loophole. Currently, if a team comes up with an idea that skirts the intent of a regulation it requires a unanimous vote on the teams’ part to change the rules mid-season. From 2021, only an 80 per cent majority will be needed to pass a vote, making it much quicker and easier to outlaw solutions that aim to negate the benefits the new car designs should bring to the racing spectacle.

Pros: The underlying aerodynamic concept should remain intact through the teams’ development process for 2021, which theoretically will translate into
closer racing.

Cons: The tighter constraints cut down on engineering freedom, while the greater ease of mid-season rule changes means that if someone does have a clever idea, it will be easier for other teams to get it banned quickly. It won’t matter if the team with the idea is large or small, reducing the chance for a surprise performance from a small outfit that has had a stroke of genius.

We can’t know for certain how the new cars will really look until the start of launch season in 2021, but in all likelihood, the renderings shown in Austin will be a be a fairly close representation. 

First and foremost, the new rules must contribute to closing up the field, and help create a level of even competition that has been absent from the sport in recent years. These rules alone will not flatten the playing field entirely, but at the very least, new regulations always provide the opportunity for some upset.

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