2026 vs 2025: Every Key Regulation Change Side by Side

The transition from the 2022-specification cars to the 2026 generation is the most extensive regulatory reset Formula 1 has carried out in a single step since the hybrid era began in 2014. Almost every measurable parameter on the car has changed: the dimensions, the weight, the power unit architecture, the aerodynamic philosophy, the fuel specification, and the safety structures.

This article places the most significant changes side by side to clarify what has actually changed and by how much.

Where possible, figures are drawn directly from the FIA’s 2026 technical regulations. Some 2025 reference figures are the maximum permitted values under those regulations rather than what any specific team actually ran, which is the appropriate comparison basis for understanding the regulatory shift.

Also see: 2026 F1 Rules Explained: The Complete Guide to Every Major Change

Car Dimensions and Weight

The physical size of an F1 car has a direct bearing on how it behaves at slow-speed circuits, how much room it occupies when racing wheel-to-wheel, and how much aerodynamic surface area it presents to the air around it. The 2026 regulations reduce the car in every relevant dimension simultaneously.

Wheelbase

The maximum permitted wheelbase in 2025 was 3600 millimeters, and several teams ran cars close to that limit, particularly those prioritizing high-speed stability at circuits like Silverstone and Spa. The 2026 maximum is 3400 millimeters, a reduction of 200 millimeters. That difference is sufficient to change the car’s mechanical balance through slow and medium-speed corners, where a shorter wheelbase requires less lock from the driver and generates less understeer when turning into a tight apex.

A shorter wheelbase also affects the car’s behavior over kerbs and bumps. Longer cars bridge across surface irregularities in a way that shorter cars do not, meaning the 2026 machines will feel the track surface more acutely through their suspension. Teams that excelled at managing ride quality on rough tracks under the previous regulations will need to relearn those setups for a car with fundamentally different mechanical geometry.

Width and Floor

Overall car width drops from 2000 millimeters to 1900 millimeters, a reduction of 100 millimeters. This is most visible at the front wing, which is 100 millimeters narrower, and has direct implications for how close two cars can race side by side before the risk of contact becomes significant. Narrower cars give drivers marginally more room to place the car on the track, and reduce the aerodynamic penalty of running close to a barrier or a rival’s bodywork.

The floor width reduction of 150 millimeters is more aerodynamically consequential than the overall width change. The floor is the primary downforce-generating surface on a 2022-era car, and reducing its width directly reduces the area over which the low-pressure region beneath the car is developed. This change is one of several that contributes to the 30 percent reduction in total downforce between the two generations.

Minimum Weight

The minimum weight in 2025 was 798 kilograms, including the driver but excluding fuel. The 2026 minimum is 768 kilograms, a reduction of 30 kilograms. Achieving this while fitting a substantially heavier electrical system, the MGU-K assembly alone has a minimum weight of 16 kilograms compared with 7 kilograms previously, required weight savings across the survival cell, bodywork, and non-structural components. A lighter car requires less energy to accelerate and generates less tyre load at a given cornering speed, both of which have positive performance consequences.

Aerodynamics

The aerodynamic regulations represent the most philosophically significant departure from the previous era. The 2022 rules were built around maximizing ground-effect downforce from sealed venturi tunnels beneath the floor. The 2026 rules remove those tunnels and introduce active aerodynamic management through moveable wing elements.

DRS vs Active Aerodynamics

In 2025, DRS allowed a single adjustable flap in the rear wing to open on designated straights, reducing drag by reducing the rear wing’s angle of attack. Activation required the pursuing driver to be within one second of the car ahead at a defined detection point. The system was available in race and qualifying conditions, but always subject to the proximity rule in races.

In 2026, the entire front and rear wing assemblies can switch between two operating states. Z-mode is the high-downforce cornering configuration; X-mode is the low-drag straight-line configuration. X-mode is available on any approved straight longer than approximately three seconds, to every driver on every lap, with no proximity requirement for standard activation. The one-second gap does still matter in 2026, but it now triggers a separate power unit advantage rather than an aerodynamic one.

The wings themselves are different. The 2026 front wing has a two-element flap connected to a rotation system. The rear wing has three elements. The lower beam wing, a fixture beneath the main rear wing plane on all cars from 2022 to 2025, has been removed entirely from the permitted bodywork envelope. These structural changes are not cosmetic; they reflect a completely different aerodynamic load distribution between the wing assemblies and the floor.

Downforce and Drag Levels

Total downforce is approximately 30 percent lower in 2026 compared with 2025-specification cars. Total drag is approximately 55 percent lower. These figures capture the combined effect of the floor changes, the wing geometry changes, the dimensional reductions, and the removal of the beam wing. The drag reduction is proportionally larger than the downforce reduction, which means the 2026 cars have a better lift-to-drag ratio than their predecessors even in Z-mode.

The practical consequence is that 2026 cars will be faster on straights for a given level of power and slower through high-speed corners than the cars they replace. The shift in balance between corner speed and straight-line speed will require teams and drivers to adapt their braking references, their throttle application points, and their tyre management strategies for every circuit on the calendar.

Floor and Diffuser

The 2025 floor used sealed venturi tunnels on each side of the car’s centerline to generate ground-effect downforce. These tunnels accelerated air beneath the car, creating a low-pressure region that pulled the car toward the track. The 2026 floor is flat across the central section, with the tunnel geometry absent. The diffuser at the rear of the car is longer and has a larger exit opening than before, compensating for some of the downforce lost with the tunnel removal. The net effect is an aerodynamically simpler underbody that is less sensitive to ride height changes and produces a cleaner wake for following cars.

Power Unit

The power unit changes for 2026 are more fundamental than any revision to the formula since the current hybrid architecture was introduced in 2014. The overall output target is similar to the previous era, but the balance between combustion and electrical power has been inverted, and one of the two motor-generator units has been deleted entirely.

ICE Output

In 2025, the best internal combustion engines produced approximately 550 kilowatts from their 1.6-liter turbocharged V6. In 2026, the ICE is targeted at approximately 400 kilowatts. The reduction reflects the regulatory decision to constrain combustion output and make up the performance difference on the electrical side. The fuel energy flow limit has dropped from 100 kilograms per hour to approximately 70 kilograms per hour (3000 megajoules per hour), and the race fuel allowance has fallen from 110 kilograms to 70 kilograms.

MGU-K Output

In 2025, the MGU-K produced a maximum of 120 kilowatts. In 2026, its maximum output is 350 kilowatts, nearly three times the previous figure. This single change transforms the MGU-K from a supplementary performance booster into a co-primary power source. At 350 kilowatts, the MGU-K alone produces more power than many complete race cars in other categories. The MGU-K’s minimum weight rises from 7 kilograms to 16 kilograms to reflect its larger physical size, and it must now be mounted within the survival cell rather than in the rear of the car.

MGU-H

In 2025, the MGU-H sat on the turbocharger shaft, recovering energy from exhaust heat and eliminating turbo lag by motoring the compressor at low engine speeds. It was one of the most technically complex components ever raced in motorsport, and a significant reason why F1 engines achieved thermal efficiency figures exceeding 50 percent. In 2026, the MGU-H does not exist. It has been deleted from the regulations entirely, primarily to reduce the cost and development complexity that made building a competitive power unit prohibitively difficult for new entrants.

Energy Store and Recovery

The Energy Store’s maximum usable delta state of charge is 4 megajoules in 2026. The maximum energy recoverable per lap via the MGU-K is 9 megajoules, compared with 2 megajoules for the MGU-K under the previous rules (the MGU-H could recover additional energy separately). The expanded recovery budget reflects the MGU-K’s dramatically increased generating capacity under braking and coasting.

MGU-K Rampdown and Override

The 2025 regulations did not include a speed-based rampdown for MGU-K deployment. In 2026, the MGU-K’s electrical output begins to reduce above 290 kilometers per hour and reaches zero at 355 kilometers per hour. This rampdown prevents the combination of X-mode aerodynamics and maximum electrical output from producing unsafe terminal velocities. The override function, available when a driver is within one second of the car ahead, extends maximum deployment to 337 kilometers per hour, replacing the aerodynamic overtaking advantage that DRS previously provided in race proximity situations.

Fuel

The fuel specification change for 2026 is complete rather than incremental. Every car in every session runs on Advanced Sustainable Fuel, a specification that permits no new fossil carbon. The fuel must be produced from non-food biomass, municipal waste, or carbon capture, and the production process must use renewable electricity.

From Fossil to Sustainable

In 2025, F1 ran on a fuel that incorporated a proportion of sustainable components but was not fully renewable. The 2026 specification removes fossil-derived fuel entirely. The Research Octane Number requirement of 95 to 102 RON is consistent with previous F1 fuel specifications, meaning the fuel’s anti-knock behavior is broadly comparable. The composition limits in Article 16 of the technical regulations govern the concentrations of specific chemical families within the fuel to maintain combustion consistency across all manufacturers’ engines.

The practical impact for spectators and fans is mainly found in the narrative around the sport’s environmental credentials. The engineering impact is felt in the combustion calibration work that manufacturers have had to undertake to optimize their engines for a fuel whose precise chemical composition differs from the fossil-derived fuels accumulated in their development databases. The teams and manufacturers who understood the new fuel’s combustion characteristics earliest will have carried an advantage into the opening races of the season.

Safety Structures

The safety regulations have been updated across several structural systems simultaneously, with the FIA’s stated goal being to improve protection in a broader range of impact scenarios without adding to the minimum weight requirement.

Roll Structure Loads

In 2025, the principal roll structure was required to withstand a combined load equivalent to 16 times the gravitational force applied in three axes simultaneously. In 2026, that requirement is 20g, a 25 percent increase. The forward roll structure’s requirements have been updated proportionally. Meeting the higher load standard with no weight increase requires optimized carbon fibre layup schedules and in some cases redesigned structural geometry rather than simply additional material.

Front Impact Structure

The 2026 front impact structure uses a two-stage deformation design that did not exist in the previous regulations. The structure now collapses in two distinct phases: an initial deformation absorbing the peak load of the primary impact, followed by a secondary deformation providing protection against the rebound impacts that accident analysis has identified as a common feature of high-speed crashes. The previous single-stage structure exhausted most of its energy absorption capacity in the primary event, leaving less protection for subsequent contacts.

Side Intrusion and Fuel Cell Protection

Cockpit side intrusion protection has been increased, with the fuel cell side protection structures required to be more than double the strength of the previous specification. This increase applies without a weight penalty, achieved through revised composite geometry and layup optimization. The fuel cell itself is subject to updated puncture and impact resistance tests that reflect the higher structural protection surrounding it.

Manufacturers

In 2025, four power unit manufacturers supplied the grid: Mercedes, Ferrari, Renault, and Honda in a transitional capacity. For 2026, the manufacturer count rises to five, with Renault no longer supplying as an independent manufacturer, Alpine instead becoming a Mercedes customer, and three new or returning names joining the field.

Mercedes and Ferrari continue as the established suppliers. Honda returns as a fully-fledged manufacturer, supplying Aston Martin. Red Bull Powertrains, in a new collaboration with Ford, supplies both Red Bull teams. Audi, having taken over Sauber, brings a clean-sheet power unit to the grid as the only genuinely new manufacturer in 2026. Cadillac enters as an 11th constructor running on customer power, with General Motors developing its own unit for a later date.

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