Airaid Kit Replacement Filter - 721-478

The Airaid 721-478 Kit Replacement Filter is a premium performance air filter engineered by Airaid to deliver high airflow and help improve horsepower and torque in your engine. Designed as a direct replacement element for compatible Airaid cold air intake systems, this DryFlow filter keeps your engine breathing cleanly without the mess of oil-based filter maintenance. Whether you're refreshing an existing Airaid intake setup or upgrading your engine's air filtration, the 721-478 is a bolt-in solution built to Airaid's exacting performance standards.

Key Features & Benefits

• DryFlow Filtration Technology: Airaid's premium DryFlow filter media operates without oil, meaning no re-oiling between service intervals and no risk of contaminating mass airflow sensors — a common concern with oiled aftermarket filters.
• High Air Flow Design: Engineered specifically to increase airflow to your engine, the 721-478 is designed to support improved horsepower and torque output compared to a restrictive stock paper filter.
• Performance Replacement Fit: Built as a kit replacement element, this filter installs directly into compatible Airaid intake kits — no adapters or fabrication required, keeping your install clean and straightforward.
• Distinctive Red Filter Construction: The signature red Airaid filter housing is easy to spot in the engine bay and signals a performance-grade component designed for enthusiasts.
• Reusable & Washable: Unlike disposable OEM paper filters, Airaid's DryFlow construction is designed for long-term use, allowing you to clean and reinstall rather than continuously replacing.
• Universal Application Versatility: Marketed as a universal air filter, the 721-478 suits a range of performance intake setups across multiple vehicle platforms wherever its dimensions and flange fit.

Specifications

• Brand: Airaid
• Part Number: 721-478
• SKU: AIR721-478
• Filter Type: DryFlow Performance Air Filter (oil-free)
• Flange Size: 4" flange
• Filter Dimensions (approx.): 10.08" base × 7" top × 8.5" height (per listing data)
• Color: Red
• Condition: New
• California Prop 65: Warning — Cancer and Reproductive Harm

Fitment

The Airaid 721-478 is classified as a universal performance air filter, meaning fitment is determined by your intake system's flange diameter and available space rather than a vehicle-specific application list. It is designed to serve as a replacement filter element for compatible Airaid intake kits. One commonly referenced application pairing in retailer data associates this filter with setups used on the 2011–2023 Ford Mustang GT and F-150 5.0L platforms, though you should verify compatibility with your specific Airaid intake kit part number before ordering.

If you are unsure whether the 721-478 is the correct replacement element for your existing Airaid intake system, contact our fitment specialists at ThreePiece.us before purchasing — we're here to help you get the right part the first time.

What's in the Box

• 1x Airaid 721-478 DryFlow Replacement Air Filter

Why Buy from ThreePiece.us

At ThreePiece.us, we stock Airaid performance air filters and intake components for enthusiasts who demand quality without the guesswork. Here's why customers choose us:

• Free Shipping on Every Order: No minimum, no surprises — every Airaid filter ships free to your door.
• Affirm Financing Available: Split your purchase into manageable payments with Affirm financing at checkout, so you can get the performance parts you need now.
• Fitment Expertise: Not sure if the 721-478 matches your intake kit? Our team can help verify compatibility before you buy — saving you time and return hassle.
• Performance Parts Focused: ThreePiece.us is built for enthusiasts. We carry wheels, tires, and performance accessories with the product knowledge to back them up.

Frequently Asked Questions

Q: Does the Airaid 721-478 require oiling?
A: No. The 721-478 uses Airaid's DryFlow filter technology, which means it operates entirely oil-free. You won't need to purchase filter oil or worry about over-oiling affecting your MAF sensor readings.

Q: What vehicles or intake kits does the 721-478 fit?
A: The 721-478 is a universal-style filter with a 4" flange. It is designed as a replacement element for compatible Airaid intake kits. Retailer data references compatibility with setups used on 2011–2023 Ford Mustang GT and F-150 5.0L applications. Always cross-reference your existing Airaid intake kit part number to confirm this is the correct replacement filter before ordering.

Q: Is the Airaid 721-478 reusable?
A: Yes. Airaid's DryFlow filters are designed to be cleaned and reused rather than discarded after a single use, making them a more cost-effective and environmentally conscious long-term solution compared to disposable OEM paper filters.

Q: What are the dimensions of the 721-478 filter?
A: Based on available listing data, the filter features a 4" flange, approximately 10.08" base diameter, 7" top diameter, and 8.5" height. Always confirm these measurements suit your intake housing before purchasing.