Writing Formula One's rule book is a thankless task. On the one hand, you have the objectives of 10 warring teams, six image-conscious engine manufacturers and tens of millions of fans; and on the other, you have the laws of physics.
Balancing it all is like spinning plates. Spread across a concert hall. With the lights turned off.
Can you make the new cars more road relevant by increasing electrification of the power unit?
No problem.
And make sure the racing is even better than before?
Yes, but ...
While ensuring the cars go even faster?
Erm, hang on ...
And make sure all ten teams are evenly matched?
Hold on a minute!
F1's governing body, the FIA, is the organisation challenged with doing all of the above in time for the 2026 season. Historically, the FIA has managed its workload by focusing on either the engine regulations or chassis regulations for any one year, but for 2026 it is doing both with a pair of rule books that are inseparably intertwined.
Due to the long lead time required for engine development, the regulations surrounding the power units were signed off midway through 2022. With little more than 18 months to go until the start of 2026, though, the chassis and aerodynamic regulations are only now approaching their deadline for publication.
The main author of the new regulations is FIA director of single seaters Nikolas Tombazis, who has dubbed the governing body's latest creation "a moderate revolution."
The still-evolving draft of the chassis and aerodynamic regulations is set to be approved by FIA's World Motor Sport Council (WMSC) on June 28, but could change past that date with approval from the F1 Commission (i.e. an agreement between a majority of teams). The hardest deadline is Jan. 1, 2025, by which point the rules need to be in a workable state to allow teams to start their aerodynamic research.
"We're not in the final set of regulations yet," Tombazis told media in Canada. "We do have quite a few things that we need to define and discuss with the teams.
"We are fully conscious of some of the concerns ... And these are things that we class as the refinements that still need to take place. So between, let's say, the end of the month, when these regulations will hopefully be published, and the start of 2025, when teams can start aerodynamic development, we do expect a reasonable amount of extra work to be done in full consultation with the teams, with FOM [Formula One Management] and everybody else. Hopefully that will then lead to some refinements that will be submitted to the World Council maybe a bit later in the year and hopefully approved."
So with time already ticking, what are the key areas of concern, and are there already possible solutions?
A power unit too far?
The biggest challenge for 2026 is of the rule makers' own creation. The goal of having an engine with a 50/50 split between electric and combustion power is admirable from an environmental perspective, but not without its problems.
The near-300% increase in electrification was signed off two years ago as a means of futureproofing the sport beyond 2026. As car manufacturers around the world look to wean their road-going products off gasoline and toward electricity, F1 felt the need to follow the trend to remain relevant.
Combined with feeding the internal combustion engine with fully synthetic fuels (capable of being dropped into existing petrol road cars), the emphasis on electrification was a key factor in tempting German automaker Audi to join the sport as well as convincing Japanese giant Honda to remain.
The peak output of the 2026 power units is expected to be even higher the current ones -- i.e. more than 1,000 horsepower -- but instead of the rough 80/20 split between internal combustion engine and energy recovery system F1 has now, it will be nearer 53/47.
The maximum deployment of electrical energy via the MGU-K (motor generator unit - kinetic) will go from 120 kilowatts (160 hp) under the current regs to a whopping 350 kw (475 hp) -- the same power output as the motor in a Formula E car. Despite the huge rise in electrical power, the maximum state of charge of the battery at any one time will remain at 4 megajoules, meaning a fully charged battery will be depleted three times as fast. To help feed the demands of the more powerful MGU-K, it will be allowed to harvest more energy under braking, with as much as 8 MJ to 9 MJ of regeneration per lap as opposed to 2 MJ under the 2014-2025 regulations.
All very impressive on paper, but in early simulations there were some clear limitations. If you simply bolted a 2026 engine into a current F1 chassis, the drag acting on the 2024-spec aerodynamics would mean the electric power on offer would be depleted midway down most straights -- resulting in slow lap times and farcical racing scenarios.
In the pursuit of faster cornering speeds, the aerodynamic surfaces of current F1 cars are designed to generate downforce in the knowledge that there will be an unavoidable byproduct of drag on the straights. As long as the time gained in the corners outweighs the time lost on the straights, the downforce/drag trade-off is easy to justify.
The current levels of downforce are set by engineers who know they can rely on a tank full of energy-dense gasoline, ready and willing to be burned by the V6 turbo engine to create 800 hp and punch a hole in the air. The MGU-K provides a 160 hp electric boost that is strategically applied around the lap, but if the battery is at risk of being depleted and the MGU-K drops out (known as "clipping"), the loss in overall power is still not disastrous to the car's progress to the next braking zone.
In 2026, a restricted fuel flow limit means the internal combustion engine will produce only 535 hp. Therefore, with the existing drag levels, cutting 475 hp of electrical power midway down the straight would feel akin to pulling a parachute from the rear of the car.
The aerodynamic solution
To make battery power go further, the FIA plans to slash drag levels in 2026, with the biggest saving coming from active aerodynamics. A more powerful version of the current drag reduction system (DRS) will be available to drivers on designated straights to reduce air resistance and ease the workload of the power unit. Unlike DRS, however, it will not be used as an overtaking aid but as a standard tool for all drivers around the lap, regardless of their track position relative to one another.
Known as "X-mode," the low-drag setting will work by opening flaps in both the rear and front wings, allowing air to pass through the wing without the buildup of pressure that creates downforce when the wing is running in its normal setting. Under braking, or at the push of a driver-activated button, the wings will return to their natural downforce-generating position, known as "Z-mode," to provide braking and cornering performance.
Combined with more restrictive aerodynamic regulations, including flatter floors, revised wing shapes and sizes and greater prescription of various bodywork surfaces, the FIA is predicting a 55% reduction in drag and a 30% reduction of downforce.
Less downforce means less grip, which in turn means drivers will spend less of the lap at full throttle. Less of the lap at full throttle will reduce the points around the lap at which the MGU-K will have to deploy full power -- again saving the precious electrical energy. Combined with that, the reduction in overall downforce will also increase the length of braking zones, adding to the opportunities for the MGU-K to top up the battery under braking.
All good news for the FIA's target of 50/50 electrification, but still bad news for the overall performance of the car. Although acceleration out of corners and the speeds on the straights will likely be higher thanks to instantly accessible electric power and reduced drag, cornering speeds are set to drop significantly.
The concerns
For the self-professed "pinnacle of motorsport," that presents a problem. There's an expectation that Formula One cars are the fastest race cars on the planet, and the reduction in downforce for 2026 has raised concerns that other single-seater formulas -- such as Formula 2, Japan's Super Formula and IndyCar -- could significantly close the gap.
"The way cars are in the draft version of the regulations -- and we need to say 'draft' because there's a lot of work to do -- the cars are not fast enough in the corners and too fast in the straights," McLaren team principal Andrea Stella said at the Canadian Grand Prix. "These two aspects need to be rebalanced."
Williams team principal James Vowles added: "It's imperative that we are still the leading series in motorsport. That's how I see us. We're the pinnacle of this. And therefore, as a result of that, we need to make sure that we're maintaining the performance and speed we have. And right now, there's a mismatch there [for 2026], fundamentally. The performance difference to an F2 car could be as small as a few seconds. And that's starting to get a little bit tight, especially when you compare it to other series around the world.
"But also these are draft regulations. I'm confident we'll get to a better solution in that regard. It's not that we're so far away, there's just a little bit more work required."
Red Bull team principal Christian Horner, whose team will build its own power units for the first time in 2026, underlined the need for enough freedom in the chassis regulations to ensure F1 isn't turned into an engine formula.
"There is going to be compromises, but what I think is important is there is enough freedom between the cars so that they don't all look identical," he said. "We will have a budget cap and need to have engineering creativity within that, so it doesn't just become a battery/fuel formula.
"[We need it to] be chassis and engine combination, so if you don't have the best engine you can compensate with the chassis and vice-a-versa. It's finding that balance that I think Nikolas [Tombazis] is very aware of and hopefully the recommendations that come back will be sensible."
Tombazis doesn't deny the cars will be slower, but with time left to determine the exact drag/downforce tradeoff, urges the wider F1 community not to panic.
"I think the fears are accurate, because people are taking a snapshot of what the regulations on a piece of paper are now and are making comments on the basis of what they see," he said in Canada. "So I don't have any concern about these issues raised by people.
"But clearly, we have full expectation to make some steps up for performance. And that's exactly why we've set the bar reasonably low to start with, so we can build up on that with the collaboration of the teams.
"To increase the downforce of these cars is actually quite easy -- if you have the regulator of freedom, I mean. And that's exactly the step we want to take.
"So I understand the comments. I don't think there's any concern these cars will be not faster than F2 or anything like that. I think that would be 100% resolved by the time we are in the final regs."
Is it too late to change the engine regs?
Perhaps the most obvious (and easiest) solution would be to reduce the reliance on battery power by tweaking the engine formula. Under the existing 2026 engine regulations, the V6 turbo's power is restricted by fuel flow (albeit via the amount of energy rather than weight of fuel), meaning upping it to take some of the strain off the battery would be easily achievable.
"I still think that the way in which the power units are planned to be used needs to be adjusted," Stella, whose McLaren team will use Mercedes engines in 2026, said. "We can still achieve a 50/50 concept, which is a nice concept, but it can be achieved in a way that doesn't put so much of our requirement on the chassis side, which then is difficult to meet.
"So I think from a power unit point of view, likewise from a chassis point of view, it's time that all parties understand that they need to contribute to the success of the sport."
The only issue is that the engine regulations were signed off in 2022 and any changes would require agreement among the power unit manufacturers. Mercedes, which is believed to be among the most advanced in its power unit programme, has made clear it is not willing to make changes.
"I think on the power unit side, that ship has sailed," Mercedes team boss Toto Wolff said. "There are teams that think they are on the back foot and other OEMs that have done a good job and that leads to the normal wrestling on regulations. But I think on the chassis side there are tweaks that are possible that we need to do, but on the engine side the process is far too advanced."
Tombazis, however, appeared to leave the door open.
"There's a slightly different position in terms of governance in the power unit, because we are already under governance agreement in relation to the power unit regulations, which means that any tweaks that may be necessary will still need to be agreed with the power unit manufacturers and cannot be done, let's say, unilaterally," he said. "But because there's, generally speaking, a very good spirit of collaboration, if there are some tweaks needed, I'm quite confident that PU manufacturers would help and be collaborative here."
Refining the solution
With the regulations still very much in draft form, the FIA says it recognises the concerns of the teams and will be open to refining the rules after the initial version is signed off by the World Motor Sport Council at the end of the month. Although the new power unit formula has presented clear challenges, the governing body has not lost sight of the need to provide cars that can race each other and ultimately deliver entertaining viewing.
A reduction in downforce should help drivers follow one another off the bat, but there is also a big effort to tidy up their aerodynamic wake to allow chasing cars to stay closer through corners. The current chassis regulations, introduced in 2022, have shown just how easily the FIA's best intentions in this area can be unpicked by teams in the pursuit of performance, and the governing body says the very prescriptive set of draft regulations for 2026 are rooted in lessons learned.
Just how restrictive those regulations remain, though, will be open to negotiation between WMSC sign off June 28 and the point at which teams are allowed to start work on them Jan. 1, 2025. In signing off a relatively extreme set of regulations at the end of the month, the FIA is giving itself some wiggle room to grant more freedom at a later date -- as long as it doesn't come at the cost of its own goals.
"Typically, teams are always a bit reluctant at implementing large changes," FIA single-seater technical director Jan Monchaux said in Canada. "So it's a bit of an ongoing compromise that needs to constantly be found.
"The approach we had, since we needed to respect the framework in terms of date of publication, the regulation as has been presented now and which hopefully will be voted, is probably the most restrictive teams will be seeing. We think it's going to be far easier in the next months to start increasing the freedom and review some aspects of the regulation which potentially currently are too far constrained than the other way around, because they will all agree on having more freedom."
Weight reduction
Weight reduction has also been a target for the FIA in the new regulations, with the governing body setting teams the target of reducing the car's mass by 30 kilograms. The main aim of weight reduction is to make the cars more nimble and easier to race, although it will also carry some minor efficiency gains that will help the electrification issue too.
However, a number of voices in the paddock believe the 30 kg reduction is close to unachievable. The increased demands on the battery and energy recovery system have seen the minimum weight for the total power unit increase from 151 kg to 185 kg despite the deletion of the 4 kg MGU-H (motor generator unit - heat), adding a potential 34 kg right there. Beefed-up crash structures for improved safety are also expected to add weight, and the counterargument that the smaller dimensions of the car -- 10 centimetres narrower and a 20 cm shorter wheelbase -- will not be enough to compensate.
"I don't think anyone will hit that weight target," Vowles said in the knowledge his Williams team still hasn't hit the minimum weight under the current regulation set. "It's going to be incredibly difficult, and I think that needs reviewing. As someone who spends their life going through marginal gains, taking weight out of a car, it's not a fun thing to do."
In response, the FIA points out that the 768 kg minimum weight is just that: a minimum weight. It is a target teams will aim for and one Tombazis believes is challenging but ultimately possible based on the wider changes to the regulations.
"We are quite determined to reduce the weight of the cars," Tombazis said. "We've been working on a range of assumptions based on work that Jan has been doing in collaboration with the teams. And we've got a range of areas where we know weight will go up, and we've got a range of areas where we know weight will go down.
"What we have as a target is based on a challenging, but what we feel is feasible, target. Clearly, we are going to be still asking teams for some estimates about the weight savings they can make and so on, and we are going through that process. But we are pretty determined to reduce the weight in a significant way."
What happens next?
With the June 28 WMSC deadline looming, it's clear the 2026 regulations are far from being finalised. What's also clear, though, is that there's enough engineering brilliance within both the teams and the FIA to solve the problems presented.
Despite the concerns raised over the Canadian Grand Prix weekend, most team bosses went on to state their belief that a valid set of regulations can be agreed upon before the end of the year. The issue may be that each team proposes a solution rooted in their own interests, but the validity of each will be for the FIA to decide.