Car

F1 2026's straightline mode will slash drag - with one major catch

by Jack Chilvers

6min read

F1 Car render 2026

One of the biggest aerodynamic changes coming to the 2026 Formula 1 regulations reset is the replacement of the Drag Reduction System (DRS) to include moveable aerodynamics on the front and rear of the F1 cars.

Aston Martin F1 car exiting garage

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Previously known as X-mode, this new overtaking aid is now known as straightline mode - and Raceteq has got an exclusive look at how much of a difference this could make when it is implemented in 2026.


Computational Fluid Dynamics (CFD) simulations, courtesy of Bramble CFD, illustrate the changes in airflow and their impact on the racecars.

Our analysis of the results of Bramble’s CFD simulations suggests that straightline mode could deliver the expected decrease in drag, but it might have one crucial drawback.

It’s worth describing why DRS - which was introduced in 2011 - reduces laptimes and helps drivers execute overtakes, and why it’s being phased out. 
F1 car in straightline mode 2026

3D render showing how straightline mode could appear on the front wing of a 2026 F1 car. All 3D renders courtesy of Just FormulaCar

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The DRS overtaking aid and its replacement

The current regulation cycle allows for the rear wing flap element to rotate and open up at certain points around the track in specific conditions. The activation of DRS leads the rear wing flap to provide less aerodynamic support to the main element of the wing.

This reduces the amount of drag and downforce generated by the wing on straights and allows for a top-speed boost, which promotes overtaking in a straight line.

In 2026, the effect of straightline mode will be similar and, in a similar vein to the rear wing, the front wing flap element will also be moveable to further reduce the downforce being generated ahead of the front axle.

F1 car with straightline mode 2026

3D render showing straightline mode active on a representative 2026 F1 rear wing

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The reason for the FIA’s decision to replace DRS with straightline mode stems from the new power units, which in 2026 include a larger proportion of energy generated by the electrical component (the motor generator unit - kinetic, or MGU-K). The introduction of Manual Override Mode gives drivers the ability to expend the battery’s energy to provide a straightline speed boost. To increase the efficiency of this mode, the FIA has moved to reduce the amount of drag cars produce in a straight line. 

This mission to reduce the amount of drag produced by cars meant that DRS would no longer have had the same effect, and so the FIA sought to replace it with a more powerful moveable aerodynamic system.

That’s where straightline mode comes into play: this low-drag setting will increase aerodynamic efficiency on the straights and provide an overtaking aid. 
F1 CFD 2026

CFD delta plot showing aerodynamic pressure on a representative 2026 F1 car with straightline mode deployed. Red/orange areas indicate a reduction in suction and blue/purple regions indicate an increase in suction

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First look at straightline mode in action 

The image above shows a delta plot from underneath a representative 2026 F1 car. It shows the response of the aerodynamic pressure acting on the surface of the car with straightline mode deployed.
 
Regions of red/orange indicate a reduction in suction, while blue/purple regions indicate an increase in suction.
 
The main elements of both the front and rear wings are red, indicating a strong reduction in circulation as their respective flap elements rotate and are no longer supporting load generation. The diffuser also suffers as a consequence of the rear wing no longer producing the supporting circulation at its exit. 
 
Interestingly, the front floor becomes purple: as it will produce more suction in straightline mode.
F1 CFD 2026

Comparison looking at the front of an F1 car with the nose and front tyres facing the viewer, showing front wheel wake pressure in corner mode (above) and straightline mode (below) - and the expected reduction caused by deployment of straightline mode

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In the comparison above, the top image shows the total pressure in the front wing wake in corner operation. With straightline mode activated in the bottom image, the losses from the wing are not only significantly reduced, but they do not peak as much due to the amount of downforce being generated by the wing by default.


In the image below, a slice through the airflow just behind the front wheels shows the impact that offloading the front wing has on the rotation of the wheel wake, which normally threatens to destabilise the bodywork downstream of the front wheels.

The inboard wheel wake, (bottom comparison, below image), is reduced and remains further outboard, away from the leading edge of the floor. The higher wake in the picture is being pulled inboard by the overall rotation of this body of wake, as denoted by arrows. This phenomenon seems to improve the total pressure being delivered to the floor, possibly increasing the amount of downforce being produced locally - as highlighted in the delta plot earlier in the article. 

F1 CFD 2026

Wake is pulled inboard - indicated by arrows - when straightline mode is active, which could have a positive effect by reducing turbulence

Going rearwards (image below, with straightline mode activated in the bottom part of the comparison), we can see that the reduction in front wheel wake losses going into the leading edge of the floor leads to a much cleaner airflow within the diffuser. The dirty air kicked up by the rear wheel contact patch also remains further outboard as, when straightline mode is deployed, the rear wing is producing less load.
F1 CFD 2026

A CFD simulation of the rear, looking towards the wing and diffuser, of a 2026 F1 car showing cleaner airflow through the diffuser when straightline mode is activated (below) compared to corner mode (above)

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Our CFD analysis therefore shows that straightline mode will significantly change car balance but not to a detrimental point and it might actually improve local load produced by the floor and diffuser. Of course, this effect might not be so pronounced given that straightline mode won’t be used in corners - as corner mode will be the default. 

Our CFD model predicts a 25% reduction in downforce when straightline mode is deployed, alongside an 18% decrease in drag overall. 

Plotting the accumulation of the drag force across the car and comparing corner mode to straightline mode, we can see how the vast majority of the drag is reduced at the rear of the car. Towards the front of the car, the drag is slightly reduced but the effect remains small.
F1 car 2026 data

Drag plot showing the reduction in drag across the car between corner mode (blue line) and straightline mode (red line)

There is one possible caveat to straightline mode: reducing the rear wing load also has an effect on wake behind the car. 

The ‘mushroom’ effect that became evident in our CFD analysis of the car itself sees a marked reduction when straightline mode is engaged, keeping the turbulent wake lower and spreading it outward. That will inevitably impact the onset flow to any car following. As a result, straightline mode may even hamper how easy it is to follow cars in 2026.
F1 CFD 2026

CFD simulation showing wake behind the 2026 F1 car in corner mode

CFD simulation showing wake being pushed lower and outwards when straightline mode is deployed

The focus in aiding overtaking is centred around deploying energy from the battery with the use of Manual Override Mode, and reducing drag by deploying straightline mode - which should hopefully be enough to overcome turbulent wake behind the cars.

All of this could well lead to improved wheel-to-wheel action, but we’ll only see the proof once the 2026 F1 season begins in earnest.

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