Audi A4 2018 Wiper Blade Sizes: What You Need to Know

The 2018 Audi A4 typically uses a 24-inch wiper blade on the driver’s side and a 20-inch blade on the passenger’s side, with a separate, smaller rear wiper if equipped (commonly around 13 inches, depending on body style and market). These sizes apply to most 2018 A4 sedans and Avants, but owners should confirm exact fitment by VIN or trim before purchase.

Why Wiper Blade Size Matters on the 2018 Audi A4

Choosing the correct wiper blade size for an Audi A4 2018 is essential not just for visibility, but also for protecting the windshield and ensuring the wiper motor and arms are not strained. While wiper blades may look universal, they are engineered to match the curvature and sweep area of specific models, including the B9-generation Audi A4 produced in 2018.

In practical terms, fitting the correct blade sizes prevents streaking, reduces noise, and ensures maximum coverage of the glass area. For an executive sedan like the Audi A4, which is often driven at high speeds and in varied weather conditions, properly sized and well-fitted wipers are a key safety component rather than a minor accessory.

Standard Wiper Blade Sizes for the 2018 Audi A4

The 2018 Audi A4 (B9 generation) front wiper setup follows a staggered-size design, with the driver’s blade longer than the passenger’s to maximize visibility without collision between arms. Rear wiper fitment depends on whether the car is a sedan (often no rear wiper) or Avant/allroad (wagon-style body with rear wiper).

Below is a breakdown of the most commonly specified wiper blade sizes for the 2018 Audi A4 by position:

• Driver’s side (front): 24 inches (approximately 600 mm)
• Passenger’s side (front): 20 inches (approximately 500 mm)
• Rear wiper (Avant / allroad, where equipped): commonly around 13 inches (approximately 330 mm), exact size can vary by brand and market, so checking by VIN or OEM part number is recommended

These sizes reflect what major aftermarket catalogues (Bosch, Valeo, Trico, and others) and Audi fitment databases list for the 2018 A4 range, but verification against your specific car’s configuration remains important, particularly for the rear wiper on Avant or allroad models.

Model Variations and Fitment Considerations

Although the 2018 Audi A4 is part of a single generation (B9), there are variations—sedan, Avant (wagon), and allroad—that can influence wiper setup, particularly at the rear. Front wiper blade sizes are generally consistent across trims and engine options, but details such as mounting style and rear blade may differ slightly by region and specification.

Sedan vs Avant vs Allroad

The main difference for wiper sizes lies in whether the car has a rear wiper. The A4 sedan typically does not include a rear wiper, while the Avant and allroad, designed for more practical, family-oriented and all-weather use, commonly feature one.

Below is an overview of how body style affects wiper configuration on a 2018 Audi A4:

• A4 Sedan (four-door saloon): Front wipers only — 24″ driver / 20″ passenger, no rear wiper in most markets.
• A4 Avant (wagon): Same 24″ / 20″ front blades, plus a rear wiper around 13″ (exact spec can vary, so OEM lookup is advised).
• A4 allroad: Mechanically close to the Avant, using the same front sizes and a similar rear wiper length, again around 13″, with minor variations by market or production batch.

Understanding which body style you own is the first step to getting the correct blades. While the front measurements are consistent, the rear blade for Avant and allroad models is better confirmed via the vehicle identification number (VIN) or by cross-checking with the existing blade.

Mounting and Aero Design

Beyond length, 2018 Audi A4 wipers are typically “aero” or beam-style blades, designed to maintain even pressure along the windshield at highway speeds. Many aftermarket suppliers offer direct-fit beam blades specifically for Audi applications, which include the correct mounting hardware integrated into the blade.

Owners should pay attention not only to the size of the blade but also to the connector type. The 2018 A4 commonly uses a specific hook or specialized arm adapter; buying “vehicle-specific” kits from major brands is often the easiest way to ensure compatibility without having to juggle separate adapters.

How to Verify the Correct Wiper Size for Your Audi A4 2018

Although the standard sizes quoted by manufacturers and parts stores are reliable for most 2018 Audi A4 models, verifying fitment is worthwhile, especially if the car was bought used, modified, or imported from another market. A quick check can prevent wasted purchases and ensure proper performance.

The following approaches are commonly recommended to confirm the correct wiper blade size for your specific car:

1. Check the owner’s manual: Audi usually lists wiper measurements or at least part numbers for front and rear blades in the manual or maintenance section.
2. Look at the existing blades: Many blades have their length printed on the rubber or plastic spine; if not, you can measure the metal/rubber section end-to-end.
3. Use the VIN at a dealer or parts site: Providing your VIN to an Audi dealer or reputable online parts retailer will yield the exact OEM part numbers and compatible sizes.
4. Use brand fitment tools: Major wiper brands (e.g., Bosch, Valeo, Trico, Rain-X) offer online lookup tools where you select year, make, and model to confirm the appropriate kit.
5. Cross-check regional specifications: If your car is an import or from a different market, confirm via regional Audi sites or specialist parts catalogues, as minor differences can exist.

By combining information from the owner’s manual, your current blades, and trusted parts catalogues, you reduce the risk of buying incorrect sizes and ensure that the new wipers will perform properly in all weather conditions.

Choosing Between OEM and Aftermarket Blades

Once you know the correct sizes—24″ for the driver’s side, 20″ for the passenger’s side, and around 13″ for the rear on Avant/allroad—the next decision is whether to purchase original Audi (OEM) blades or high-quality aftermarket equivalents. Both approaches can work well, but each has its advantages.

Here are some of the main differences between OEM and aftermarket blades for the 2018 Audi A4:

• OEM blades: Designed specifically for the A4’s windshield curvature and mounting system, ensuring factory-level fit and quiet operation, but usually at a higher price.
• Premium aftermarket blades: Brands like Bosch, Valeo, and others offer direct-fit beam blades that match OEM performance, often with added coatings (e.g., water-repellent) and slightly lower cost.
• Budget aftermarket blades: Cheaper options may fit physically but can produce more noise, streaks, and shorter lifespan, making them less economical over time.
• All-weather or winter blades: For regions with heavy snow and ice, specialized winter blades with encased frames can prevent ice buildup, improving durability and sweep consistency.

Balancing cost, performance, and local climate needs will guide your choice. For a vehicle like the Audi A4, many owners lean toward OEM or reputable premium aftermarket blades to preserve visibility and comfort, especially on long or high-speed journeys.

Maintenance Tips to Extend Wiper Blade Life

Correct size is only part of the equation; maintenance plays a major role in how effectively the wipers on a 2018 Audi A4 clear the windshield and how often they need replacement. Neglected blades can degrade quickly, regardless of brand or spec.

The following maintenance practices can help you get the most from your 24″ and 20″ front blades (and rear blade, where fitted):

1. Clean the rubber regularly: Wipe the wiper edges with a damp cloth to remove dirt, road film, and debris, especially after winter or dusty conditions.
2. Avoid using wipers on dry glass: Always activate the washer fluid first to reduce friction and prevent the rubber from tearing or chattering.
3. Lift blades in freezing conditions: In severe cold, lifting blades off the glass when parked can prevent them from freezing to the windshield and tearing when activated.
4. Replace annually or when streaking appears: Most blades perform best for about 6–12 months under normal use; persistent streaks, smearing, or skipping signal it’s time for new ones.
5. Check arm tension and alignment: If new blades still perform poorly, the wiper arms may be misaligned or have weak springs, requiring inspection by a technician.

By following these steps, you can ensure that your correctly sized wiper blades provide clean, consistent visibility, reducing strain on both your eyes and the wiper system itself.

Summary

For a 2018 Audi A4, the commonly specified wiper blade sizes are 24 inches for the driver’s side and 20 inches for the passenger’s side, with a rear blade of around 13 inches on Avant and allroad models where a rear wiper is fitted. These measurements align with major parts catalogues and typical OEM specifications, though confirming with the owner’s manual or via VIN remains the safest approach, especially for the rear.

Correctly sized, good-quality wiper blades—paired with simple maintenance—are crucial for safe driving in all weather conditions. Owners of the 2018 Audi A4 should ensure they select blades that match both the stated lengths and the correct mounting style, choosing either OEM or reputable aftermarket options to maintain the car’s visibility and comfort on the road.