K&N High-Flow Universal Clamp-On Air Filter, 3 in Flange — 5.75 in Height, Washable

The K&N RU-5111 is a washable, reusable clamp-on high-flow air filter designed to boost airflow and last the lifetime of your vehicle.

This tapered, cone-style universal air filter from K&N combines multi-layer cotton gauze media with a pliable rubber flange to deliver consistent high air flow while resisting vibration and leakage. Built for a wide array of intake setups, the RU-5111 clamps on quickly, arrives pre-oiled for immediate use, and replaces many disposable filters with a single long-term solution. It’s manufactured in the USA and covered by a one-year limited warranty.

How does the RU-5111 improve engine breathing?

The RU-5111 uses multiple layers of specially treated cotton gauze to allow more air to pass through while trapping contaminants. Increased airflow can support better throttle response and engine efficiency without the recurring cost of disposable filters.

• Four-layer cotton gauze filtration for fine particle capture
• Pre-oiled media to optimize immediate filtration performance
• Designed to increase airflow compared with standard paper elements

What makes installation and fitment straightforward?

This clamp-on unit features a molded, flexible rubber flange that stretches over a 3-inch inlet and secures with a hose clamp. Its tapered, universal shape fits many intake tubes and aftermarket setups, simplifying installation across different vehicles and custom applications.

• 0.75" flange length for reliable clamp engagement
• 3-inch flange diameter for common intake openings
• Lightweight cone shape that adapts to various engine bays

How often do I need to service the filter?

K&N filters are washable and reusable, so maintenance is periodic rather than frequent replacement. Under normal highway driving, clean the filter about every 75,000 miles, with actual intervals depending on driving conditions and environment.

• Washable media—no disposable replacements required
• Suggested cleaning interval: ~75,000 miles in typical highway use
• Cleaning restores airflow and filtration performance

What are the RU-5111’s durability and warranty details?

Constructed with rugged materials, the RU-5111 is engineered to endure vibration and repeated cleanings. K&N backs the product with a one-year limited warranty and emphasizes long service life as an alternative to single-use filters.

• Durable molded rubber flange resists cracking and leaks
• Premium construction intended for long-term reuse
• 1-year limited warranty from the manufacturer

Who is this for: The K&N RU-5111 fits vehicle owners and enthusiasts who want a simple, reusable upgrade to improve airflow and reduce waste. It’s ideal for custom intakes, older cars with compatible tubing, and drivers who prefer lower long-term maintenance costs over recurring disposable filters. Choose this model if you need a 3-inch clamp-on solution with a tapered cone profile and lifetime usability.