K&N Universal Air Filter 4in Flange / 5-3/8in Base / 4-1/2in Top / 6in Height K&N Engineering KNNRU-4550
K&N Universal Air Filter 4in Flange / 5-3/8in Base / 4-1/2in Top / 6in Height K&N Engineering KNNRU-4550
K&N Universal Air Filter 4in Flange / 5-3/8in Base / 4-1/2in Top / 6in Height K&N Engineering KNNRU-4550
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K&N Universal Air Filter 4in Flange / 5-3/8in Base / 4-1/2in Top / 6in Height

KNNRU-4550
024844373809
Air Filters - Universal Fit
20+ Units In Stock - Ships Next Business Day
$ 78.99
$ 78.99

SKU: RU-4550 | UPC: 024844373809

K&N Universal Air Filter 4in Flange / 5-3/8in Base / 4-1/2in Top / 6in Height RU-4550

The K&N RU-4550 is a universal clamp-on air filter designed for racing vehicles radio-controlled cars generators snowmobiles tractors and more. It fits applications like 1999-2000 Honda Civic models 2001-2002 BMW 525i 2009 Mazda MX-5 Miata 2002 Mini Cooper S and 2004 Volkswagen Golf GTI VR6. This pre-oiled filter increases airflow for higher horsepower and acceleration while trapping contaminants with four layers of cotton gauze.

Key Features

  • 4 Layers of Protection: Multiple layers of premium cotton gauze treated with a tacking agent create a mesh that blocks harmful contaminants from reaching the engine.
  • Clean Once Every 5 Years: Requires cleaning only every 75000 miles under normal highway driving or 5 years at 15000 miles per year.
  • Easy Installation: Pre-oiled and ready to use for quick clamp-on setup and cost-effective performance gains.
  • Engineered Power: State-of-the-art media boosts horsepower acceleration and overall engine performance.
  • Rugged Construction: Built with durable premium materials and vibration-absorbing rubber flanges that stretch up to 1/16 inch for secure fit.

Product Notes

  • Flanges constructed from molded pliable rubber for secure attachment on 4in intakes regardless of angle or offset.
  • Washable and reusable to reduce landfill waste from disposable filters.
  • Product weight 1.6 lb ships in box 8.25in x 8.19in x 7.19in.

Installation Notes

  • Professional installation recommended.
  • Clamp-on design fits 4in flange diameter centered with 1.063in flange length no inner wire.
  • Stretch flange up to 1.5mm for in-between sizes re-oil with 1.52 oz after cleaning.

This Part Fits

Year Make Model Submodel
2001-2002 BMW 525i Base
1999-2000 Honda Civic CX
1999-2000 Honda Civic DX
1999-2000 Honda Civic EX
1999-2000 Honda Civic GX
1999-2000 Honda Civic HX
1999-2000 Honda Civic LX
1999-2000 Honda Civic Si
1999 Honda Civic Value Package
2009 Mazda MX-5 Miata Sport
2009 Mazda MX-5 Miata SV
2009 Mazda MX-5 Miata Touring
2002 Mini Cooper S
2004 Volkswagen Golf GTI VR6

Why Choose K&N?

  • Proven performance in racing and street applications worldwide.
  • Washable reusable design lasts a lifetime with proper care.
  • 1-Year Limited Warranty covers defects in materials and workmanship.

Frequently Asked Questions

  • Q: Will the RU-4550 fit my 1999-2000 Honda Civic LX?
    A: Yes it is confirmed to fit 1999-2000 Honda Civic LX and other submodels like CX DX EX GX HX Si with 4in intake.
  • Q: What material is used in this filter?
    A: Four layers of premium cotton gauze media treated with a tacking agent in a round tapered shape with rubber top and flanges.
  • Q: What warranty applies and how do I maintain it?
    A: Backed by 1-Year Limited Warranty clean every 75000 miles wash with K&N cleaner re-oil with 1.52 oz provided oil.

Shipping & Handling

  • Method: Ground Shipping
  • Availability: In stock - ships same or next business day
  • Packaging: Protective box 8.25 in x 8.19 in x 7.19 in
  • Weight: 1.6 lb

Request For Information

Have questions about K&N Universal Air Filter 4in Flange / 5-3/8in Base / 4-1/2in Top / 6in Height? Fill out the form below and we'll get back to you by the next business day.
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