Rear diffuser
ExtérieurAverage price
300€ - 2500€
The rear diffuser is a body component located under the rear bumper of a vehicle. Directly inspired by motorsport, its primary role is aerodynamic. It is designed to accelerate the airflow passing underneath the car, thereby creating a low-pressure zone. This phenomenon generates downforce that presses the car to the ground, significantly improving stability and grip at high speeds, especially in corners. The vertical fins, known as 'strakes', help channel this air and minimize turbulence. Beyond its primary function, the rear diffuser has become an essential styling element on sporty vehicles. It gives the rear end a more aggressive and technical appearance, often seamlessly integrating the exhaust tips. Made of plastic on production models or carbon fiber on high-performance cars for weight savings and increased rigidity, the diffuser is the perfect synthesis of performance engineering and automotive design. It transforms the rear of a vehicle from a simple body termination into a functional area that actively works to improve handling.
Benefits
- ✓Improved stability and grip at high speed
- ✓Reduction of aerodynamic drag and lift
- ✓Sportier, more aggressive and sleek aesthetics
- ✓Integration and enhancement of exhaust tips
Learn more
What is a rear diffuser and what is its purpose?
The rear diffuser, sometimes called an extractor, is an aerodynamic component located at the lowest part of the rear bumper. Far from being a mere aesthetic gimmick, its design is directly inherited from motorsport. Its main function is to manage the airflow passing underneath the vehicle. By featuring a surface that gradually expands towards the rear, the diffuser allows the high-speed air flowing under the car to slow down and expand. According to Bernoulli's principle, this deceleration increases air pressure, creating a differential with the lower pressure beneath the chassis. This results in a suction effect that glues the car to the ground, a phenomenon known as downforce.
The concrete benefits of a rear diffuser
The installation or presence of a functional diffuser offers several key benefits, especially for dynamic driving:
The different types of diffusers
Not all diffusers are created equal. There are two main categories:
Aesthetic diffusers: On many production vehicles, even those equipped with sport trims like 'GT Line' or 'R-Line', the diffuser has a primarily stylistic role. Made of ABS plastic or polypropylene, its shape mimics that of a real diffuser, but its aerodynamic impact is negligible. It is mainly used to enhance the model's visual identity.
Functional diffusers: Reserved for sports cars and supercars, these diffusers are the result of extensive wind tunnel testing. They are often larger, with more pronounced channels and strakes. The material of choice is carbon fiber, chosen for its lightness and extreme rigidity, which prevents deformation under aerodynamic load. These parts are an integral part of a complete aerodynamic package, working in concert with the flat floor, side skirts, and rear spoiler.
Equipment for everyone?
Initially the exclusive domain of racing cars, the diffuser has become widely democratized. Today, it is found on a wide range of vehicles, from hot hatches to powerful sedans, as well as dynamic SUVs. For the majority of drivers, its contribution will be purely visual, contributing to the pleasure of owning a car with a sleek and assertive design. For track-driving enthusiasts or high-performance vehicle owners, the diffuser is an essential technical ally that pushes the limits of grip and performance.
Finitions équipées
105 finition(s) proposent cet équipement
Alfa Romeo Alfa Romeo 4C
4C Carbon Edition (1st generation) (2015-2018)
Alfa Romeo Alfa Romeo Brera
Brera S (1st and only generation) (2010)
Alfa Romeo Alfa Romeo Stelvio
Quadrifoglio (1st generation - phase 2 facelift) (2020-2023)
Audi Audi A8
S line (D5 / 5th generation) (2018-2026)
Audi Audi Cabriolet
S line (A5 Cabriolet 2nd generation) (2017-2024)
Audi Audi Q3
Black Line (2nd generation) (2020-2026)
Audi Audi Q3
S line (1st generation) (2011-2018)
Audi Audi Q4 e-tron
Competition (1st generation) (2022-2026)
Audi Audi Q5
SQ5 (1st and 2nd generation trim variants) (2013-2024)
Audi Audi Q8
RS Q8 Performance / Special Edition (facelift) (2024-2026)
Audi Audi R8
R8 V10 Coupé (1st generation) (2010-2015)
Audi Audi R8
R8 V10 Plus Coupé (2nd generation) (2015-2018)
Audi Audi RS Q3
RS Q3 Sportback (2nd generation) (2020-2026)
Audi Audi RS Q3
RS Q3 performance (1st generation) (2016-2018)
Audi Audi RS Q8
RS Q8 Carbon Pack (1st generation) (2020-2023)
Audi Audi RS Q8
RS Q8 performance Carbon Black (2nd generation) (2024-2026)
Audi Audi RS5
RS5 Carbon Edition (2nd generation) (2021-2023)
Audi Audi RS6
RS6 Avant Carbon Black (C8) (2021-2025)
Audi Audi RS7
RS 7 Sportback Carbon Black (2nd generation C8) (2021-2026)
Audi Audi RS7
RS 7 Sportback performance Carbon (2nd generation C8) (2023-2026)
Associated equipment
Aerodynamic Package
An aerodynamic package is a set of bodywork components specifically designed to manage and optimize airflow around a moving vehicle. Its primary objective is twofold: to reduce aerodynamic drag (the drag coefficient, or Cd) and to increase downforce. Reducing drag helps improve energy efficiency—thereby lowering fuel consumption or electric range—and increases top speed. Increasing downforce, on the other hand, presses the car onto the road at high speeds, significantly improving tire grip, straight-line stability, and cornering speed. A typical aero package consists of several elements working in synergy: a front splitter that channels air under the car, side skirts that prevent air from escaping out the sides, a rear diffuser that accelerates air extraction from beneath the vehicle to create a low-pressure zone, and a rear wing or spoiler that manages airflow separation and generates downforce on the rear axle. Initially reserved for racing cars, these packages are now common on production sports cars (GTI, RS, AMG, M) and are even offered as options on more standard models, combining performance gains with aesthetic appeal.
Rear spoiler
The rear spoiler, often referred to as a wing or spoiler, is a body component attached to the rear of the vehicle, typically on the trunk lid or tailgate. Although it is a powerful symbol of sportiness and performance, its primary role is aerodynamic. Its function is to manage the airflow passing over the roof and sides of the car at high speed. By disrupting or redirecting this airflow, the spoiler reduces lift (the tendency of the vehicle to be lifted by the air) and increases downforce on the rear axle. This extra downforce presses the car to the ground, thereby improving stability, tire grip, and safety during rapid direction changes or high-speed braking. There are several types of spoilers, from simple, discreet body-integrated lips to more aggressive raised wings, as well as active systems that deploy automatically depending on speed. Beyond its technical function, the rear spoiler is an essential design element that gives the vehicle a dynamic and athletic character.
Sport Exhaust
A sport exhaust is an aftermarket exhaust system that replaces the original equipment manufacturer (OEM) part to optimize a vehicle's performance, exhaust note, and aesthetics. Its design primarily aims to reduce backpressure, a phenomenon that slows down gas evacuation and limits engine efficiency. By using larger diameter piping and more direct-flow mufflers, it allows the engine to 'breathe' more freely. This gain in efficiency translates to a noticeable increase in horsepower and torque. Crafted from high-grade materials such as stainless steel (304L/316L) or titanium, these systems are not only lighter than stock mild steel setups, but also much more corrosion-resistant. Beyond performance, a sport exhaust transforms the driving experience with a richer, deeper, and more aggressive sound. The most sophisticated versions feature controlled valves, allowing the sound level to be modulated on demand, switching from a discreet city mode to a race track sound. It is a popular modification among enthusiasts to personalize their car and unleash its true character.
Sport spoiler
The sport spoiler, also known as a rear wing, is a body component added to the rear of a vehicle for both aesthetic and functional reasons. Its primary role is aerodynamic: it is designed to manipulate the airflow passing over and around the car in motion. By generating downforce on the rear axle, the spoiler pushes the car down at high speeds. This increased rear tire grip significantly improves stability, handling in fast corners, and braking efficiency. Beyond its technical function, the sport spoiler is a symbol of performance and sportiness. It radically alters the vehicle's silhouette, giving it a more aggressive and dynamic look. It is found as standard equipment on sports models and high-end trims (GT Line, S-Line, AMG, etc.), but it is also a popular aftermarket accessory for customization. Spoilers can be fixed, integrated into the bodywork, or active (mobile), deploying automatically at a certain speed to optimize aerodynamics as needed. Materials range from standard ABS plastic to lighter and more prestigious carbon fiber.
Dual exhaust system
A dual exhaust system is a vehicle exhaust configuration where combustion gases are evacuated through two separate outlets at the rear. Highly sought after on sports and high-end models, this equipment serves a dual purpose: aesthetic and functional. Visually, it gives the rear of the vehicle a more symmetrical, aggressive, and prestigious look, emphasizing its high-performance character. Technically, there are two main types. The first, purely cosmetic, consists of a single exhaust pipe that splits into two just before the bumper. The second, a 'true' dual system, features two separate pipes running from the manifold or the middle of the vehicle. This latter configuration is the most effective for improving performance. By facilitating gas evacuation, it reduces backpressure in the engine, allowing it to 'breathe' more freely. The result is an increase, often modest but real, in power and torque, as well as a deeper, sportier engine note. Therefore, a dual exhaust is much more than just a stylistic device; it is a feature that enhances the driving experience and the dynamic identity of a car.