Rear Diffusers

When constructing a race car, no matter whether it’s a purpose built track machine or a modified production vehicle, car builders try to achieve an aerodynamic balance between drag and downforce. Minimizing drag reduces the air resistance encountered by the car, allowing it to go faster. Downforce is necessary so the tires stay firmly planted on the track surface for optimal power delivery, steering and braking. Diffusers, air dams and side skirts combine to increase down force on race cars. If you want to make your machine look like it’s ready for the track, check out our selection of diffusers.

Show items:
Sort by:
    • (4 reviews)
      # sp7298
      Rear Diffuser by Duraflex®. Accelerate the velocity of the airflow underneath your car with this Rear Diffuser. At speed, it'll decrease the pressure under the car with a resulting increase in downforce. Increased downforce will help...
      Helps to elevate your vehicle above the massesProprietary polymer blend for maximum flexibility and strength
      $47.00 - $683.10
    • (2 reviews)
      # sp7334
      Carbon Fiber Rear Diffuser by Carbon Creations®. Accelerate the velocity of the airflow underneath your car with this Rear Diffuser. At speed, the rear diffuser will decrease the pressure under the car with a resulting increase in...
      Racing inspired aerodynamics and styleUsed by professionals in auto racing, drifting and drag racing
      $159.00 - $1,060.00
    • (0 reviews)
      # sp131984
      Aero Rear Diffuser by Vorsteiner®. Material: Autoclaved 1×1 Pre-Preg Carbon Fiber with UV Inhibiting Clear Lacquer Coating. Vorsteiner's Autoclaved Pre-Preg Carbon Fiber structure gives Vorsteiner parts superior stiffness, aerospace...
      Designed with refinement in mind to offer the ultimate in stylePerfect solution to give your vehicle an aggressive yet elegant look
      $1,230.25 - $3,130.25
    • (1 review)
      # sp298
      Carbon Fiber Rear Diffuser by Seibon®. Give your car a high-tech aerodynamic look with this carbon fiber rear diffuser cover. A rear diffuser cover can redirect airflow coming from underneath the car to transition smoothly into the...
      Finished in glossy clear coat that will not chip or flakeAerodynamically designed
      $442.00 - $799.00
    • (0 reviews)
      # sp802
      Rear Diffuser by Aero Function®. Add aggressive visual style to the lower section of your rear bumper cover with an add-on Rear Diffuser from Aero Function. Contoured to fit perfectly on your vehicle, the rear diffuser skirt installs...
      Adds on to the lower section of rear bumper cover to add more aggressive styleEnhances aerodynamics with contours that reduce airflow drag
      $63.00 - $1,655.10
    • (0 reviews)
      # sp30139
      Rear Diffuser by Liberty Walk®. This diffuser creates a vacuum at the back of the vehicle, which draws air more quickly underneath. Reduce turbulence and ensure the smooth airflow with this top-notch diffuser while making your vehicle...
      Adds a stylish edge to your vehicleWill improve aerodynamics of your auto
      $550.00 - $7,020.00
    • (1 review)
      # sp17214
      Rear Diffuser by Anderson Composites®. If you want to get the most out of your vehicle, this this superior product by Anderson Composites is just what you need. Designed with the utmost care and attention to detail and manufactured from...
      Designed to comply with strict quality standardsManufactured from high-grade materials
      $449.10 - $1,349.10
    • (0 reviews)
      # sp93669
      Rear Diffuser by Agency Power®. Blending sleek, racing style with superior functionality, this superior add-on delivers a mean, intimidating look that commands attention while enhancing aerodynamics and reducing the air drag to boost...
      Sleek, low-profile design adds heart-racing edge to the rear end’s lookIntegrates with the bumper to reduce aerodynamic drag and maximize downforce
      $250.00 - $1,600.00
    • (1 review)
      # sp7321
      Rear Diffuser by RKSport®. An Exhaust Diffuser accelerates the velocity of the airflow underneath the car. At speed, it decreases the pressure under the car with a resulting increase in downforce. Increased downforce helps improve your...
      Adds to the appearance of your vehicleDesigned to increase downforce and traction
      $309.20 - $1,892.06
    • (0 reviews)
      # sp8108
      German Rush™ V10 Style Rear Diffuser by Vertical Doors®. Upgrade the rear end of your automobile with this premium-grade diffuser by Vertical Doors to give it that unique aggressive look that will separate it from the mundane masses....
      Gives your vehicle a stylish race-ready lookHelps increase downforce and aerodynamic efficiency
      $1,595.00 - $2,605.50
    • (0 reviews)
      # sp47706
      CA Super Coupes™ Rear Diffuser by Vertical Doors®. Upgrade the rear end of your automobile with this premium-grade diffuser by Vertical Doors to give it that unique aggressive look that will separate it from the mundane masses....
      Gives your vehicle a stylish race-ready lookHelps increase downforce and aerodynamic efficiency
      $809.10 - $863.10
    • (0 reviews)
      # sp85848
      Rear Diffuser by ARK Performance®. Equip your vehicle with this superior rear diffuser from ARK Performance to reduce aerodynamic drag and maximize downforce which allows for snappy acceleration, astounding performance, agile handling,...
      Designed to boost your vehicle's style and aerodynamic efficiencyOptimizes airflow to reduce drag and maximize downforce
      $254.15 - $823.65
    • (0 reviews)
      # sp7359
      Rear Diffuser by Borla®. Improve the airflow under your car for increased downforce while giving it great race track looks with this Rear Diffuser. It’s the perfect complement to your Borla exhaust system. The Rear Diffuser is made...
      Reduces turbulence and drag at the mufflers and underbodyImproves airflow for increased downforce
      $315.99 - $696.99
    • (0 reviews)
      # sp49250
      Rear Diffuser by KBD®. 1 Piece. Material: Polyurethane. Comes unpainted. Add a sporty look to your prized vehicle with this cutting-edge rear diffuser from KBD. This eye-catching upgrade instantly provides a dash of that heart-racing...
      Designed to accelerate the flow of air under the carIncreases downforce and improves aerodynamic grip
      $220.00 - $559.20
    • (1 review)
      # sp7344
      Havoc Rear Diffuser by IVS®. This kit is just what you need to achieve that very style you've seen in a magazine. All the components are reaction injection molded urethane and ensure the same perfect durability, fit, and finish as OEM...
      Adds a sporty look to your carGreatly improves aerodynamics
      $637.50 - $841.50
    • (0 reviews)
      # sp121655
      C7 Revorix Style Rear Diffuser by DefenderWorx®. 2 Pieces. Turn your valuable investment into an extra-ordinary racing machine on the streets with this top-of-the-range diffuser designed by DefenderWorx. This first-grade product is...
      Perfect to add a touch of sportiness to your vehicle’s profileHelps to increase traction and stability on the racetrack
      $2,034.24 - $2,671.24
    • (0 reviews)
      # sp135556
      Rear Diffuser by Extreme Dimensions®. This product will make your car look like it's glued to the road. And its flexible Urethane construction will ensure it stays looking good. Installation typically requires sanding, trimming, and...
      Stylish and aerodynamicFlexible and durable
      $136.00
    • (1 review)
      # sp127810
      Rear Diffuser by Chrome & Carbon®. This product is a fantastic solution for those who want to dress up their vehicle and make it look distinctive. Its breakthrough design, top-quality materials, and unique design will surely make you...
      Designed to customize your vehicle and give it a unique lookPerfect way to elevate your automobile above the masses
      $765.00 - $1,162.80
    • (0 reviews)
      # sp137590
      Aero I Rear Lower Bumper Diffuser by Better Bodies®. Material: Polyurethane. Comes unpainted. Primed. This top-grade product is expertly made in compliance with stringent industry standards to offer a fusion of a well-balanced design...
      Designed to enhance the styling and down force of rear end of vehicleEasy Install, simply bolts onto the factory rear bumper
      $357.00
    • (0 reviews)
      # sp137594
      Rear Diffuser by Better Bodies®. Material: Polyurethane. Comes unpainted. Primed. Now you can have the exotic look without having to change your entire rear bumper. Very easy installation.
      Built to take quality to a new level and deliver peak performanceMeticulously engineered with top-of-the-line technology
      $285.31 - $499.94
    • (0 reviews)
      # mpn4520785179
      50R-SS™ Rear Half Spoiler by Kuhl Racing®. Material: Fiberglass. Comes unpainted. This aero parts are pursued through the aerodynamics and are based on racing design. Obtaining data with using a 3D scanner and cutting parts with...
      The highest grade materials and the latest technologiesCreated by professionals to meet your requirements
      $569.00
    • (0 reviews)
      # sp144597
      Rear Diffuser by Kuhl Racing®.This top-grade product is expertly made in compliance with stringent industry standards to offer a fusion of a well-balanced design and high level of craftsmanship. Manufactured from industry-leading...
      The highest grade materials and the latest technologiesCreated by professionals to meet your requirements
      $479.00 - $659.00
    • (0 reviews)
      # sp144353
      Center Exhaust Finned Diffuser by NR Automobile®. Center Exhaust Finned Diffuser by NR Automobile®, 1 Piece. Add an aggressive look to your center exhaust 991 Carrera, Carrera S, C4, and C4S with the NR Auto 991 rear finned diffuser....
      Brings the ultimate in style and performanceExpertly manufactured from the highest grade materials
      $995.00 - $1,395.00
    • (0 reviews)
      # mpn4540397567
      Exhaust Surround by NR Automobile®, 1 Piece. Carbon Fiber. Add a distinctive look to your Cayman's exhaust with Nr Auto carbon fiber surround. Easy installation. This top-grade product is expertly made in compliance with stringent...
      Brings the ultimate in style and performanceExpertly manufactured from the highest grade materials
      $349.00
    • (0 reviews)
      # sp144363
      Type 1 Rear Diffuser by NR Automobile®. Type 1 Rear Diffuser by NR Automobile®, 1 Piece. Add a bolder look to your stock rear diffuser with the Type 1 add on diffuser. Diffuser installs on top of your original diffuser between the...
      Brings the ultimate in style and performanceExpertly manufactured from the highest grade materials
      $495.00
    • (0 reviews)
      # sp144368
      Vsport Rear Diffuser by NR Automobile®. Vsport Rear Diffuser by NR Automobile®, 1 Piece. Add a bolder look to your Porsche 991 Turbo rear bumper with NR Auto VSport finned diffuser. This part will give you Turbo more stability at high...
      Brings the ultimate in style and performanceExpertly manufactured from the highest grade materials
      $1,095.00 - $1,595.00
    • (0 reviews)
      # sp144755
      Rear Diffuser by Stillen®. Polyurethane Construction. Ready to Prime and Paint. Personalize the Nissan L33 sedans lower tail end of the Altima (valance) with something that isnt very smooth or stale. The Fifth Gen Altimas share...
      Part Comes Pre-Installed with 3M Automotive Tape (Same as OEM uses)No Cutting or Modification to Bumper - Removable
      $215.67 - $395.00
    • (0 reviews)
      # sp127495
      Rear Bumper with Diffuser by D2S®. This product is made of high-quality materials to serve you for years to come. Designed using state-of-the-art technology and with customers in mind, this product by D2S will last a lifetime. It will...
      Custom high performance styleComes with everything required for installation
      $384.18 - $8,799.34
    • (0 reviews)
      # mpn4495456661
      Exhaust Shield by AutoTecknic®. Material: Carbon fiber. Installation type: Clip-in. Carbon Type: Twill Weave. This is AutoTecknic's brand new pre-preg dry carbon fiber exhaust shield cover. It is made with 2x2 twill weave carbon fiber...
      Engineered to provide easy installationUnsurpassed in design and performance
      $400.00
    • (0 reviews)
      # sp132877
      Rear Diffuser by Vicrez®. This top-grade product is expertly made in compliance with stringent industry standards to offer a fusion of a well-balanced design and high level of craftsmanship. Manufactured from industry-leading materials...
      OEM - Fitment, Quality, DurabilityPolyurethane is Practically Unbreakable
      $689.00 - $749.00




    Featured Brands

    Although some body mods increase drag to create downforce, this tradeoff is necessary for overall vehicle performance. However, there are component choices a builder can make that maximize downforce without creating excessive drag. Such is the case with a rear diffuser. When combined with an air dam and side skirts, a rear diffuser functions to increase the velocity of the air flowing underneath the car and increase downforce and traction at the tires.

    According to Bernoulli’s Principle, when the velocity of air increases, its pressure decreases. This means that the air pressure above the car is greater, and this greater pressure exerted downward provides the necessary downforce. Although components like rear wings can also be used to provide downforce, they create much more aerodynamic drag while doing so than a rear diffuser. The diffuser provides the space for the high velocity, low pressure air flow to decelerate and expand at the rear of the vehicle, creating a pressure differential and more downforce. Diffusers also typically have dividers that allow the air flow to transition to the airstream at the back of the car without creating turbulence and drag.

    Of course, the above description applies mainly to a car constructed expressly for racing. Such cars usually have smoother undercarriages to facilitate the increased air flow velocity, and they are driven at much higher speeds than are allowable on the highway, so the average street driven car will not realize all of a diffuser’s benefits. But we know that the visual appeal of a custom rear diffuser and aerodynamic body components in general is just as, if not more important to street driven car owners than functionality, which is why we have the extensive selection of diffusers you see on the page before you.

    We offer rear diffusers for most popular cars in materials including carbon fiber, aluminum, urethane, fiberglass, fiberglass composite, ABS plastic and stainless steel. Depending on application, some are designed to be a fully custom addition, while others are replacements for the OE diffuser but are manufactured in an upgraded material like carbon fiber. Some applications are designed to be used with specific exhaust systems. And because each of our rear diffusers is carefully designed for a specific model, regardless of your choice you can count on ease of fitment, and an appearance that will command attention and perfectly complement your vehicle’s styling.

    Related Categories

    Guides & Articles

    Useful articles fast to read and guides easy to understand written by mechanics and car enthusiasts to turn your shopping experience with CARiD into a pleasure

    • Spoilers
      January 26, 2016
      Will Adding a Spoiler Make My Car More...
      A simple way to answer this question would be with a "yes". However, the science of properly managing airflow to create beneficial automotive aerodynamics is, quite...
      by Michael Grayen
    • Body Kits
      December 30, 2015
      What Type of Body Kit Material Should I Choose?
      If you're reading this, you've probably decided the factory stock appearance of your car, while attractive, is rather staid and unexciting. You know that modifying...
      by Timothy Zahl
    • Body Kits
      December 29, 2015
      Body Kit Installation | Weekend DIY, or...
      At CARiD, we understand how deeply the appeal of side skirts, rear diffusers, aero wings, air dams, custom replacement bumper covers, and other components included in...
      by Michael Grayen
    • Body Kits
      December 17, 2015
      Are Body Kits for Show or for Go?
      Full body kits are inspired by the look and functionality of body panel refinements made to racecars after relentless amounts of wind tunnel testing and aerodynamic...
      by Timothy Zahl
    • Bumpers
      October 06, 2014
      How Do I Repair Or Replace My Plastic Painted...
      The purpose of automobile bumpers is to protect functional and cosmetic areas of the car from damage during low-speed impacts. For many decades, bumpers were heavy...
      by Timothy Zahl

    Diffusers Reviews

    Average rating:  4.5  4.5 - 13 reviews
    4 of 5
    Rear Diffuser
    It looks amazing and was a really easy piece to install. Only issue is that it is a really tight fit. Since the carbon fiber has zero give the corners do pop out a little bit. Nothing that is going to cause it to fall off or anything, but you do constantly need to hit them back in after driving.
    Posted by Jason Clevenstine (Puyallup, WA) / March 13, 20182015 Dodge Charger
    Was this review helpful for you? Yes
    View More
    Related Rear Diffusers Pages


    Low Prices Price match guarantee
    In-House Experts We know our products
    Guaranteed Fitment Always the correct part
    Easy Returns Quick & Hassle Free

    All manufacturer names, symbols, and descriptions, used in our images and text are used solely for identification purposes only. It is neither inferred nor implied that any item sold by CARiD.com is a product authorized by or in any way connected with any vehicle manufacturers displayed on this page.

    SECURE SHOPPING