F1 Ground Effect: The Aerodynamic Revolution
How the floor generates 50% of modern car downforce
Introduction
F1 Ground Effect: How the Floor Revolutionises Aerodynamics
Ground effect in Formula 1 now represents nearly 50% of a car's total aerodynamic downforce. This technology, reintroduced with the 2022 regulations, has transformed F1 car design philosophy and how they behave on track. Understanding the floor and Venturi tunnels is essential to grasp why modern cars stick to the ground like never before.
Unlike wings that generate downforce by deflecting air upward, ground effect creates a low-pressure zone under the car. This pressure difference between top and bottom literally "sucks" the chassis toward the asphalt, offering phenomenal grip with minimal drag.
What is Ground Effect? Physical Principles
Ground effect relies on a fundamental principle of fluid physics: Bernoulli's theorem. When a fluid (here, air) accelerates, its pressure decreases. By forcing air to accelerate under the car, a low-pressure zone is created that generates downforce.
Technical diagram of F1 ground effect, Venturi tunnels and accelerated airflow
Bernoulli's Theorem Applied to F1
Imagine air as water in a pipe. When the pipe narrows, water must accelerate to maintain the same flow rate. This acceleration is accompanied by a pressure drop.
Under an F1 car, exactly this happens:
- Air enters under the car from the front
- The space between the floor and ground narrows (Venturi tunnels)
- Air accelerates to pass through this reduced space
- Pressure drops, creating a "suction" downward
- The rear diffuser slows air and reinjects it into the wake
Difference from Traditional Wings
| Characteristic | Wings | Ground Effect |
|---|---|---|
| Principle | Air deflection | Air acceleration |
| Drag generated | High | Low |
| Aero efficiency | Medium | Very high |
| Wake sensitivity | Strong | Reduced |
| Share of total downforce | ~50% | ~50% |
Ground effect's major advantage: it generates downforce with less drag than wings. This is called aerodynamic efficiency.
The Floor: Heart of Ground Effect
A modern F1 floor is anything but "flat". It's a complex sculptural piece with channels, tunnels and meticulously optimised profiles.
2022-2025 Floor Anatomy
Front zone (splitter):
- Horizontal blade that cuts air under the chassis
- Creates the first low-pressure zone
- Protects Venturi tunnel entrance
Venturi tunnels:
- Profiled channels running along each side of the car
- Section that progressively narrows toward the rear
- Responsible for air acceleration and pressure drop
Central zone:
- Generally flat for regulations
- Included the "plank" (wooden board) to control ride height
- Critical space for airflow
Diffuser:
- Rear section that expands upward
- Slows air to recover pressure
- Maximises air extraction from under the car
Materials and Construction
The floor is manufactured in carbon fibre with honeycomb structures for rigidity. It must withstand aerodynamic forces of several tonnes while weighing as little as possible.
| Element | Material | Function |
|---|---|---|
| Main structure | Carbon | Rigidity, lightness |
| Edges | Reinforced carbon | Impact resistance |
| Plank | Jabroc wood + titanium | Regulatory wear measurement |
| Aero surfaces | Laminated carbon | Smooth profiles |
Venturi Tunnels: The Key Innovation
Venturi tunnels are the aerodynamic signature of F1 cars since 2022. These channels sculpted into the floor are responsible for most of the ground effect.
How Tunnels Work
Entry (throat): Wide opening at tunnel front, air enters at moderate speed.
Convergent section: Tunnel progressively narrows, forcing air to accelerate. Speed can locally reach 300+ km/h.
Throat (col): Narrowest point of tunnel, maximum speed, minimum pressure. This is where downforce is generated.
Divergent section: Tunnel expands toward diffuser, air slows and pressure rises.
Team Optimisation
Each team has developed its own interpretation of Venturi tunnels:
Red Bull RB20 (2024): Very aggressive tunnels with narrow throat section, maximising downforce but requiring very precise ride height.
McLaren MCL38 (2024): Progressive tunnels with wider throat section, offering more tolerance to ride height variations.
Ferrari SF-24 (2024): Hybrid approach with variable geometry tunnels depending on circuits.
The Diffuser: Critical Air Extractor
The diffuser is often considered the most important element of F1 aerodynamics. Located at the rear of the floor, it "pumps" air from under the car.
Diffuser Role
- Air extraction: Creates suction effect that accelerates flow in tunnels
- Pressure recovery: Progressively slows air to avoid separation
- Rear wing connection: Diffuser air interacts with rear wing
Diffuser Regulations
The FIA imposes strict dimensions to limit ground effect:
| Parameter | 2025 Value |
|---|---|
| Maximum height | 175 mm |
| Maximum angle | ~14 degrees |
| Width | Limited by floor |
| Start | 175 mm before rear axle |
Beam Wing and Interaction
The beam wing (secondary wing between diffuser and rear wing) optimises interaction between these two elements. It accelerates air above the diffuser, increasing the pumping effect.
Ground Effect History: From the 80s to 2022
Ground effect isn't a recent invention. Formula 1 explored it, banned it, then reintroduced it over decades.
The Original Era (1977-1982)
Lotus 78 (1977): Colin Chapman introduces the first side skirts that seal the car's underside. Ground effect explodes.
Lotus 79 (1978): The first true "ground effect car". Mario Andretti becomes world champion with a revolutionary car.
Brabham BT46B (1978): Gordon Murray's "fan car" uses a fan to suck air from under the car. Banned after a single victory.
The Ban (1983-2021)
The FIA banned side skirts in 1983 for safety reasons. Without sealing, ground effect became unpredictable and dangerous. Regulations then imposed raised flat floors, drastically reducing ground effect.
Evolution of restrictions:
- 1983: Skirt ban
- 1994: Mandatory flat and raised floor
- 1995-2021: Marginal ground effect, wings dominant
The Return (2022-present)
The 2022 regulations officially reintroduced ground effect with integrated Venturi tunnels. The objective: allow cars to follow each other more closely.
Differences from the 80s:
- No mobile skirts (passive sealing by ground)
- Fully regulated floor
- Imposed tunnel dimensions
- Standardised diffuser
Porpoising: Side Effect of Ground Effect
The 2022 regulations revealed an unexpected phenomenon: porpoising. This vertical car oscillation dominated technical discussions that season.
What is Porpoising?
Porpoising is a self-sustaining oscillation caused by ground effect itself:
- Car generates lots of downforce
- Downforce pushes car toward ground
- Floor gets too close to ground
- Airflow "stalls" (aerodynamic stall)
- Downforce disappears abruptly
- Suspensions push car back up
- Flow re-establishes, downforce returns
- Cycle repeats
Impact on 2022 Teams
| Team | Severity | Solution Adopted |
|---|---|---|
| Mercedes | Critical | Increased ride height (performance loss) |
| Ferrari | Moderate | Suspension modifications |
| Red Bull | Low | Optimised floor design |
| Aston Martin | Severe | Complete mid-season overhaul |
Technical Solutions
Increase ride height: Reduces porpoising but sacrifices ground effect.
Stiffen suspensions: Limits oscillations but degrades mechanical behaviour.
Modify floor: Reduces stall sensitivity but can cost downforce.
FIA Technical Directive (2023): FIA imposed raised floor edges to naturally reduce porpoising.
Comparison: Aerodynamic Downforce 2021 vs 2022+
The regulation change profoundly modified downforce distribution on cars.
Downforce Distribution
| Source | 2021 (pre-regulation) | 2022+ (ground effect) |
|---|---|---|
| Front wing | ~25% | ~20% |
| Rear wing | ~35% | ~25% |
| Floor | ~20% | ~45% |
| Bodywork | ~20% | ~10% |
Comparative Performance
| Metric | 2021 | 2022 | 2024 |
|---|---|---|---|
| Max downforce (at 250 km/h) | ~1800 kg | ~1600 kg | ~1750 kg |
| Aero efficiency (L/D) | ~4.5 | ~5.0 | ~5.5 |
| Wake sensitivity | Very high | Reduced | Low |
Note: In 2022, total downforce initially decreased, but efficiency (downforce/drag ratio) increased. Teams have since recovered lost downforce while maintaining this better efficiency.
Impact on Overtaking
The 2022 regulations' main objective was to facilitate overtaking. Ground effect directly contributes.
Why Cars Can Follow
With old regulations, a car following another lost up to 40% of its downforce in the wake ("dirty air"). Wings, disrupted by turbulence, no longer worked properly.
With ground effect, most downforce comes from under the car. The wake disturbs this zone less. FIA studies show:
| Distance Behind | 2021 Downforce Loss | 2022+ Downforce Loss |
|---|---|---|
| 20 metres | -40% | -18% |
| 10 metres | -47% | -24% |
| 5 metres | -55% | -30% |
Overtaking Statistics
FIA data confirms improvement:
- 2021: Average 43 overtakes per race
- 2022: Average 56 overtakes per race (+30%)
- 2024: Average 52 overtakes per race (stabilisation)
FAQ: Ground Effect in Formula 1
Why was ground effect banned?
Ground effect from 1977-1982 was dangerously unpredictable. Mobile side skirts could jam or detach suddenly, causing serious accidents. Several drivers were injured or killed in accidents related to sudden downforce loss. The FIA preferred to ban this technology until it could be safely mastered.
Can the floor touch the ground?
No, regulations impose a wooden plank (plank) under the floor that must not wear more than one millimetre during the race. If wear exceeds this limit, the driver is disqualified. This guarantees minimum ride height for safety and sporting fairness.
How do teams simulate ground effect?
Teams use two main tools: CFD (Computational Fluid Dynamics) for numerical simulations, and wind tunnel for physical tests. In the wind tunnel, ground is simulated by a rolling belt that reproduces relative movement between car and track. These methods are complementary and heavily regulated by the FIA.
Does ground effect work in the rain?
Ground effect is considerably reduced on wet track. Water enters under the car and disrupts airflow in Venturi tunnels. Additionally, wet tyres spray enormous amounts of water that "floods" the floor. This is why F1 performance drops proportionally more than touring car performance in rain.
What will be ground effect evolution in 2026?
The 2026 regulations will retain ground effect but introduce active aerodynamics. Venturi tunnels will remain present, but cars will be smaller and lighter. The objective is to maintain ground effect advantages (easier overtaking) while adding new strategic possibilities with mobile wings.
Ground effect has transformed Formula 1 by enabling more efficient cars and more spectacular racing. To understand the other aerodynamic revolution, discover our feature on DRS and its future replacement by active aerodynamics.
