K&N Air Filter Oil 1 Gallon (Red) — Restores Oiled Cotton Filter Performance & Dust Trapping

K&N Air Filter Oil (1 gallon, part 99-0551) is a concentrated, red oil formulated to restore and maintain the contaminant-trapping performance of oiled K&N cotton air filters.

If you own a K&N high-flow oiled cotton air filter, using the correct oil when you service the element is essential to regain its original dirt-trapping efficiency and airflow balance. This 1-gallon container supplies enough oil for multiple clean-and-reoil cycles, and the formula is engineered to stay suspended across the filter pleats so particles are captured without clogging the media prematurely. Follow the cleaning kit instructions to apply the right amount after washing and drying the filter.

How does this oil restore filter performance?

After a wash cycle, the filter media needs fresh oil to rebuild the electrostatic and mechanical capture properties that stop dust and debris. K&N oil re-saturates the cotton pleats so particles are intercepted while preserving airflow for engine efficiency. Proper application ensures the pleats remain evenly coated and the filter performs close to factory specifications.

• Red formula designed for K&N oiled cotton filters
• Penetrates pleats and stays suspended for consistent capture
• Restores airflow balance and dust-trapping capability
• Large 1-gallon volume for multiple service cycles

What’s the correct way to apply the 1-gallon oil?

Application requires a measured, even coating—too little and contaminants pass through; too much and airflow can be restricted. Use the dosing instructions included with your K&N cleaning kit or an approved applicator to distribute oil across each pleat and allow time for absorption before reinstalling. Wipe away any visible excess from exterior surfaces to avoid runoff.

• Clean and fully dry the filter before oiling
• Apply evenly along pleats; avoid pooling
• Allow absorption time per kit instructions before use
• Use recommended amounts — the gallon supplies many applications

Will this oil work with other filters or brands?

K&N Air Filter Oil is specifically formulated for K&N oiled cotton filters to match their media and pleat structure. While some users may apply it to other oiled aftermarket filters, performance and compatibility are optimized for K&N products. For best results, pair this oil with K&N cleaning kits and follow the manufacturer's guidance.

• Formulated for K&N oiled cotton high-flow filters
• Optimized viscosity and adhesion for K&N pleats
• Works best when used with K&N cleaning kits
• Not guaranteed for non-K&N filter designs

How much product does one gallon cover?

A single 1-gallon container yields enough oil for many filter service cycles, depending on filter size and frequency of maintenance. Small automotive or motorcycle filters require less oil than large off-road or industrial elements. When dosing correctly, a gallon is a cost-effective option for owners who perform regular filter maintenance or service multiple vehicles.

• Large capacity designed for repeated re-oiling
• Coverage varies by filter size and application technique
• Ideal for shops, fleets, or frequent DIY maintainers
• Store in a cool, capped container between uses

Who is this for: K&N Air Filter Oil 1 Gallon (99-0551) is aimed at vehicle owners, DIY mechanics, performance enthusiasts, and service shops that use oiled K&N high-flow cotton air filters and want a reliable, concentrated supply for repeated maintenance. Choose this size if you perform regular re-oiling, service multiple filters, or prefer the economy of a bulk container while following K&N's cleaning and application instructions.