K&N High-Flow Engine Air Filter for Infiniti/Nissan (33-2399) — Washable, Reusable, Lifetime Warranty

This premium replacement air filter swaps directly into the factory air box to boost intake flow without major modification. Built from multilayer cotton gauze and finished with rugged construction, it’s engineered for long service life, reduced disposable-waste, and straightforward maintenance. K&N tests its filters under demanding conditions and backs them with a limited lifetime warranty, making this a popular upgrade for drivers who want reliable performance gains and lower ongoing filter costs.

How will this filter affect my car's performance?

Upgrading to the K&N high-flow filter increases the volume of clean air available to the engine, which can improve throttle responsiveness and can help engines breathe easier under load. Gains are vehicle-dependent and most noticeable during acceleration and at higher RPMs. The filter’s media balances filtration and flow so you retain protection from contaminants while allowing improved airflow.

• High-flow cotton gauze media increases intake airflow compared with many stock paper filters
• Designed to support smoother throttle response and potential power benefits under real-world conditions
• Engineered to trap dust and particles while maintaining airflow

What maintenance does a washable K&N filter require?

K&N filters are pre-oiled and ready for installation and only need periodic cleaning instead of frequent replacement. Under typical highway driving the suggested cleaning interval is about every 75,000 miles; more frequent service may be required in dusty environments. Cleaning uses K&N cleaning and re-oiling products and can be completed at home with basic tools.

• Clean every ~75,000 miles under normal highway conditions
• Use K&N cleaner and re-oil for best results
• Simple removal and reinstall—no complex modifications

Which vehicles is this filter compatible with?

This specific K&N part (33-2399) is designed to fit a range of Infiniti and Nissan models from mid-2000s through late 2010s. It slips into the factory airbox and retains OEM-style fitment so installation is quick and reversible. Always check fitment against your vehicle year and model before purchasing.

• Infiniti: G35 (2007–2008), G37 (2008–2013), Q40 (2015), Q60 (2014–2015), QX50 (2014–2017)
• Nissan: 350Z (2007–2009), 370Z (2009–2020), Fairlady Z (2009–2017), Skyline models (2007–2014 depending on trim)
• Direct-replacement design for easy drop-in installation

Why choose a K&N lifetime filter over disposable paper filters?

K&N’s washable filter reduces ongoing filter purchases and waste by serving for the life of the vehicle when maintained correctly. The multi-layer media and treated cotton gauze provide durable filtration while offering durability and consistent performance. K&N’s limited lifetime warranty and U.S.-based manufacturing add confidence for owners seeking a long-term filtration solution.

• Washable and reusable—reduces landfill waste and replacement cost
• Constructed with multiple cotton gauze layers and a tackifying treatment for contaminant capture
• Proudly made in the USA and supported by a limited lifetime warranty

Who is this filter for? Drivers of compatible Infiniti and Nissan models who want a dependable, long-lasting intake filter that improves airflow, lowers lifetime filter costs, and reduces replacement frequency. It’s well suited to owners who perform routine maintenance, drive in a variety of conditions, and prefer an easy, bolt-in upgrade that’s tested for real-world and track-level durability.