Why Side Skirts Matter for Your Nissan Altima

Your Nissan Altima is already a reliable and stylish sedan, but adding side skirts can take its appearance and performance to the next level. Side skirts—also called rocker panels or side splitters—are aerodynamic body components mounted along the lower edge of your vehicle, just below the doors. They aren’t just cosmetic add-ons; properly designed side skirts can improve airflow, reduce drag, and give your Altima a more grounded, aggressive stance. This comprehensive guide covers everything you need to know before buying side skirts for your Nissan Altima, from materials and fitment to installation and maintenance. Whether you’re after a subtle OEM+ look or a full street-racing aesthetic, the right side skirts will make your Altima stand out while delivering real functional benefits.

What Are Side Skirts and How Do They Work?

Side skirts are aerodynamic panels that connect the front and rear wheel wells along the side of the car. Their primary purpose is to manage airflow under the vehicle. When air flows underneath a car, it creates turbulence and lift, especially at higher speeds. Side skirts help channel air smoothly along the sides, reducing the amount of air that gets trapped under the chassis. This reduces lift, improves high-speed stability, and can even increase fuel efficiency by minimizing drag. For a daily-driven Nissan Altima, these aerodynamic gains might be modest, but they become more noticeable if you’ve lowered the suspension or added a front splitter. Beyond aerodynamics, side skirts protect the rocker panels from road debris, stones, and salt, preserving the factory paint and preventing rust. They also hide the pinch welds and underbody structure, giving the car a cleaner, more finished appearance.

Benefits of Installing Side Skirts on Your Nissan Altima

  • Enhanced curb appeal: Side skirts visually lower the car and create a more streamlined profile. Even a simple lip-style skirt can make the Altima look sportier without being over-the-top.
  • Improved aerodynamics: By reducing underbody turbulence, side skirts can improve high-speed stability and slightly reduce drag. This is especially beneficial if you’ve installed other aero parts like a front spoiler or rear diffuser.
  • Rock and debris protection: The lower body of your Altima is vulnerable to chips, scratches, and corrosion. Side skirts act as a sacrificial barrier, absorbing impacts that would otherwise damage the painted body panels.
  • Increased resale value (potential): Tastefully installed aftermarket accessories can make your car more appealing to buyers who want a customized look—especially if the parts are high-quality and well-maintained.
  • Personalization: With so many styles available—from subtle to race-bred—side skirts let you express your personal taste. You can match them to other aero components or choose a contrasting finish like carbon fiber or matte black.

Key Factors to Consider When Choosing Side Skirts

1. Material

The material of your side skirts affects weight, durability, cost, and appearance. Here’s a breakdown of the most common options:

  • Fiberglass: Lightweight and affordable, fiberglass is a popular choice for budget builds. It can be painted to match the car but is more prone to cracking under impact or extreme cold. Fiberglass skirts require care during installation and are best suited for show cars or lightly driven vehicles.
  • Polyurethane (ABS plastic or Duraflex): This is the most practical material for daily drivers. Polyurethane side skirts are flexible, impact-resistant, and easy to install. They can survive minor bumps and scrapes without cracking, and they hold paint well. Most OEM-style and aftermarket street skirts use polyurethane.
  • Carbon fiber: The premium choice for weight savings and visual impact. Carbon fiber skirts are extremely strong and lightweight, but they are also the most expensive. They often come in a glossy or matte weave finish that adds a high-performance look. Carbon fiber is best for owners who want to minimize weight and are willing to invest in high-end parts.
  • Steel or aluminum: Rare on modern sedans, but some off-road or rally-style skirts use metal. Not recommended for the Altima due to weight and corrosion risks.

2. Design and Style

Side skirts range from almost invisible to overtly race-inspired. Consider the overall look you want:

  • OEM-style / subtle lip: These skirts follow the factory body lines and add a slight extension. They look like they came from the factory and blend well with unmodified cars.
  • Aggressive / tuner style: Featuring sharp angles, pronounced fins, or deep scoops, these skirts make a statement. They pair well with aftermarket bumpers, rear diffusers, and a lowered suspension.
  • Racing / JDM-inspired: Often with canards or multi-layered designs, these are for the enthusiast who wants a track-ready appearance. They may be less practical for daily driving due to lower ground clearance.

3. Fitment and Compatibility

This is arguably the most critical factor. Side skirts must be specifically designed for your Nissan Altima’s model year (and sometimes sub-model like the Altima SR or Altima Hybrid). Even small differences in body shape can cause gaps, misalignment, or the need for extensive modification. Always check the product description for exact fitment years and trim levels. Reputable manufacturers mold their skirts to match the contours of the OEM rocker panels. If you have a different body kit (front and rear bumpers), make sure the side skirts match the design language and mounting points. Some skirts are meant to be used with specific front and rear lips.

4. Installation Method

Installation complexity varies widely. Common methods include:

  • Adhesive tape only (3M VHB): Some lightweight polyurethane skirts can be attached using automotive-grade double-sided tape. This is the easiest DIY method, but it may not hold up well in extreme weather or high-speed driving.
  • Screws and rivets: Most side skirts require drilling into the rocker panel or the underbody. This provides a secure, permanent mount. Professional installation is recommended if you’re not comfortable with power tools or bodywork.
  • Clip-on or bracket systems: Some skirts attach using brackets that bolt to existing factory holes (like those for the jacking points). This is less invasive and removable, but the fit may not be as tight.

Before buying, research the specific installation requirements. Some skirts come pre-drilled with mounting holes, while others require you to drill them yourself. Also consider whether you need to remove the factory rocker panel trim.

5. Budget

Side skirt prices can range from under $100 for basic unpainted polyurethane to over $1000 for painted, name-brand carbon fiber. Don’t forget to factor in additional costs: painting, installation (if not DIY), and potential hardware. A good rule of thumb: spending more on a reputable brand often saves headaches with fitment and durability. However, many budget-friendly options from brands like Duraflex or Extreme Dimensions offer decent quality for the price.

How to Choose the Right Side Skirts for Your Nissan Altima

Now that you understand the factors, here’s a step-by-step approach:

  1. Determine your goal: Are you building a show car, a daily driver with a sporty edge, or a track-focused machine? Your answer will guide material and design choices.
  2. Check compatibility: Note your Altima’s exact year and trim. Visit forums like Altima Forum to see what other owners have installed. Many members post reviews and photos of side skirts.
  3. Decide on material based on use: For daily driving, polyurethane is best. For garage queens or show cars, fiberglass or carbon fiber may be acceptable.
  4. Set a realistic budget: Include painting and installation costs. A $150 unpainted skirt may cost $250 to paint and install professionally, totaling $400.
  5. Research brands and read reviews: Brands like Stillen, Duraflex, 5 Axis, and VIS Racing offer Altima-specific skirts. Look for authentic customer feedback on sites like American Custom Parts or CarID.
  6. Visualize the look: Search for photos of installed skirts on Altimas of the same generation. Instagram, Altima forums, and YouTube are excellent resources.
  7. Consider future modifications: If you plan to lower the car or add a full body kit, choose skirts that will remain compatible and not scrape on driveways.

Installation Overview: DIY or Professional?

Installing side skirts can be a satisfying weekend project if you have basic mechanical skill, but it’s not for everyone. Here’s what’s typically involved:

  1. Preparation: Clean the rocker panel area thoroughly. Remove any existing trim or mudguards if needed. Dry-fit the skirt to check alignment before any adhesive or drilling.
  2. Marking and drilling: For screw-mount skirts, use a marker to indicate hole positions. Drill pilot holes carefully to avoid damaging the inner panel or wiring. Apply anti-rust primer to any exposed metal.
  3. Attaching the skirt: Apply the provided adhesive (if any) and then secure with screws or rivets along the bottom edge. For tape-only installation, use a heat gun to warm the tape before applying firm pressure for 30–60 seconds.
  4. Finishing: Check the seam with the front bumper and rear bumper. Some skirts require minor trimming or modification to align perfectly. Fill any gaps with body filler if needed (painting will cover it).

If you’re not confident in drilling into your car’s body, visit a local auto body shop or a performance tuning garage. Professional installation typically costs $150–$400 depending on complexity and painting requirements. A professional will also ensure that the undercoating and sealing are done correctly to prevent rust.

Maintaining Your Side Skirts

Proper care keeps your side skirts looking new and lasts longer.

  • Regular washing: Dirt and road salt can accumulate in the crevices. Use a gentle car shampoo and a soft brush to clean the skirts, especially the edges. Avoid high-pressure washers at close range, as they may dislodge adhesive.
  • Inspect for damage: After rough roads or winter, check for cracks, loose screws, or peeling clear coat. Address chips in painted skirts promptly with touch-up paint to prevent moisture from seeping under the paint.
  • Winter considerations: In snowy climates, side skirts can accumulate ice and snow, adding weight and potentially blocking airflow. Knock off large chunks gently. For plastic skirts, avoid using ice scrapers directly on them.
  • Polishing and waxing: For painted or carbon fiber skirts, apply a spray wax or paint sealant every few months to protect against UV rays and chemicals.
  • Protect from impacts: Be mindful of tall curbs, parking stops, and steep driveways. Some skirts lower the car’s clearance, so extra caution is needed.

Common Mistakes to Avoid When Buying Side Skirts

  • Ignoring model year differences: A 2013-2015 Altima skirt won’t fit a 2019. Always double-check the fitment range.
  • Choosing cheap fiberglass for a daily driver: Fiberglass cracks easily from road debris and temperature changes. Stick with polyurethane for reliability.
  • Forgetting about painting: Many aftermarket skirts come unpainted (primed black or gray). Factor in painting costs and lead time. Consider buying pre-painted skirts if available for your color code.
  • Poor installation leading to vibration or falling: Skirts that aren’t securely attached can flap at highway speeds or even detach. Use enough mounting points and follow the instructions.
  • Not accounting for ground clearance: Lowering your Altima + aggressive side skirts may make it impossible to drive over speed bumps. Measure your current clearance and compare it to the skirt’s drop.

Top Brands and Where to Buy

Here are some reputable sources for Nissan Altima side skirts, with links to help you start your research:

  • Stillen: Known for high-quality performance parts, Stillen offers aero components for many Nissan models. Stillen Official Site – check their Altima section.
  • Duraflex / Extreme Dimensions: One of the largest manufacturers of aftermarket body kits. Their skirts are made of polyurethane and come in many styles. Duraflex Website
  • VIS Racing: Offers carbon fiber options for those seeking lightweight performance. VIS Racing Products
  • CarID: A retailer that aggregates many brands, allowing you to compare prices and read reviews. CarID Side Skirts for Altima
  • Altima Forums: Sites like Altima Forum have classifieds and community reviews where you can find used skirts or get real-world feedback.

Conclusion

Choosing the perfect side skirts for your Nissan Altima comes down to balancing aesthetics, function, material, and budget. For most Altima owners, polyurethane skirts offer the best combination of durability, ease of installation, and style. Take the time to verify fitment for your specific model year, read verified customer reviews, and consider professional installation if you’re not comfortable with drilling or painting. When installed correctly and maintained well, side skirts will transform the look of your Altima from a standard sedan into a custom, sporty ride—and they’ll also contribute to better aerodynamics and underbody protection. Whether you’re looking for a mild upgrade or an aggressive street presence, the right side skirts will give your Altima the finishing touch it deserves.